The extent and persistence of damage to the GBR ecosystem will depend to a large degree on the amount of change in the world’s climate and on the resilience of the GBR ecosystem to such change.

A number of natural pressures occur; including cyclones; crown of thorns starfish outbreaks; and sudden large influxes of freshwater from extreme weather events.

The known and potential threats include . diversity of mangroves . . diversity of seagrass land use change that contributes to sediment; nutrient and pesticide run off to the property severe weather events; including floods and cyclones . dugong . species of whales O crown of thorns starfish outbreaks species of dolphins humpback whale calving . loss of physical and ecological connectivity between habitats . . marine turtle altered hydrology and salinity barrier to hydrological flows green turtle breeding marine turtle rookeries . . modification of natural coastal and riverine . processes 242 species of birds 22 seabird species breeding (cays and some continental islands have globally significant breeding sites) plant species diversity and endemism habitat degradation and fragmentation shipping and boating incidents; including collisions with marine mammals and or sea turtles . . . . coral cays. poor water quality and pollution (for example from land based erosion; dredging; run off and waste discharge) . marine debris and litter illegal fishing introduction of exotic plants and animals O . altered aesthetic environment . increased human presence (for example disturbance of sea turtle and bird nesting sites through noise; direct harassment; lighting and increasing vessel traffic) the potential effects of climate change. 12 EPBC Act referral guidelines for the Outstanding Universal Value of the Great Barrier Reef World Heritage Area 3.

The extent and persistence of damage to the GBR ecosystem will depend to a large degree on the amount of change in the world’s climate and on the resilience of the GBR ecosystem to such change.

A number of natural pressures occur; including cyclones; crown of thorns starfish outbreaks; and sudden large influxes of freshwater from extreme weather events.

Climate change; poor water quality from land based run off; impacts from coastal development; and some remaining impacts of fishing remain the major threats to the future vitality of the Great Barrier Reef.

Climate change remains the most serious threat to the Great Barrier Reef.

The extent and persistence of these impacts depends to a large degree on how effectively the issue of rising levels of greenhouse gases is addressed worldwide.

Factors external to the property climate change; coastal development and land based run off are affecting the ecosystem as are some impacts of direct use.

The decline was attributable to a range of factors; including the high exchange rate of the Australian dollar; increased competition from international destinations; extreme weather events and the global financial crisis.

The Great Barrier Reef Tourism Climate Change Action Strategy 2009 2012 resulted in a range of products being developed to assist the tourism industry to reduce its climate footprint; including case studies; operator workshops; an online tourism operator’s emissions calculator; climate incident response plans and climate action standards in both the Climate Action Certification and ECO Certification programs.

For built heritage; the threats from climate change and direct use are the most serious. 个 High impact; Increasing Changes to the Great Barrier Reef ecosystem have serious economic Impact on economic implications for Reef dependent industries; such as tourism and fishing; and for adjacent communities.

Threats from climate change have already been witnessed and all parts of the ecosystem are vulnerable to its increasing effects with coral reef habitats the most vulnerable.

Climate change has both direct and indirect effects.

The rate and extent of increases in global greenhouse gas concentrations drive climate change.

Increased concentrations of greenhouse gases (particularly carbon dioxide) in the atmosphere result in more heat being trapped; increasing the Earth’s temperature.

The atmosphere and oceans have warmed; the amounts of snow and ice have diminished; sea level has risen; and the concentrations of greenhouse gases have increased.

Factors influencing the Region’s values A number of climate change variables are already changing and; based on a combination of global and regional climate models and observations; are projected to alter substantially in the Great Barrier Reef over the next 50 years. 31;32;33;34 It is likely that climate change will drive global changes in prominent weather characteristics and events such as cyclones; heavy rainfall; droughts; air temperature and prevailing winds. 31;35;36 For example; while cyclones and other extreme weather events are a natural part of the weather cycle in tropical areas (see Section 3.2.2); the global climate system is now warmer and moister than it was 50 years ago; and this is increasing the chances of intense weather events.37; Concentrations of carbon dioxide have increased by 40 per cent since 1750; primarily from fossil fuel emissions and secondarily as a result of changes in land use.39;40 The mean rates of ind ease in atmospheric concentrations of carbon dioxide; methane and nitrous oxide over the past century are unprecedented in the last 22;000 years; and are now at concentrations unprecedented in at least the last 800;000 years.40 Over the last five years; global carbon dioxide levels have continued to increase at a rate similar to that of the last 50 years; increasing from 386 to 397 parts per million from July 2008 to December 2013 (Figure 6.5).

More than half the observed increase of 0.6 degrees Celsius in global mean surface (air) temperature from 1951 to 2010 is very likely due to anthropogenic greenhouse gas emissions it is likely that anthropogenic influence has made a substantial contribution to surface temperature increases over Australia.44 Globally; each of the past three decades has been significantly warmer than all the previous decades in the instrumental record and the first decade of the twenty first century has been the warmest. 39 Regionally; mean temperatures are increasing.

Strong ocean warming is projected for tropical regions.30 Whatever climate scenario is used; it is predicted that by 2035 the average sea surface temperature will be warmer than any previously recorded; and by 2100 average sea temperatures off north eastern Australia could be about 2.5 degrees Celsius warmer than the present average.

Global average sea level has risen by 0.18 centimetres per year from 1961 to 2003.47 The total rise from 1901 to 2010 was 19 centimetres.48 Around Australia; and in the Great Barrier Reef; the fastest rates of sea level rise are in the north (Figure 6.6 and see Section 3.2.5).49;50 The frequency of extreme sea level events (storm driven waves and surge) increased by a factor of about three during the twentieth century.

The ocean is already getting warmer and pH is decreasing 32;34;38; (a) (b) 3. 2. 1. wwtul slow 0. 1980 1990 2000 2005 2010) 2015 2015 Figure 6.5 Changes in global atmospheric carbon dioxide concentrations Global carbon dioxide concentrations in the atmosphere have been rising.

Extreme El Niño occurrences are projected to increase. 6.3.2 Vulnerability of the ecosystem to climate change Current and future climate change related threats to the Region’s ecosystem include sea temperature increases; altered ocean currents; changed weather patterns; ocean acidification and sea level rise.

The 2013 water quality scientific consensus statement concluded that key Great Barrier Reef ecosystems are showing declining trends in condition due to continuing poor water quality; cumulative impacts of climate change and increasing intensity of extreme events’.

Pelagic foraging seabirds are highly vulnerable to changes in ocean currents.74 There is evidence that climate change has driven the ranges of Australian seabirds further south; reduced breeding success and Changes to ocean altered breeding timing for some species.74 Altered ocean circulation patterns may also affect the transport currents may of eggs and larvae of many animals within and among Great Barrier Reef habitats and influence species disrupt transport of nutrients and distributions.

Weather pattern As the climate changes; the capacity of hard corals to grow and reproduce will be increasingly shifts may increase compromised with flow on effects on other species dependent on coral reefs.

Cairns However; climate change induced shifts in weather patterns that affect the frequency; intensity or distribution of disturbance events will have important implications for the Region.45;68;91;92;93 Additionally; it is thought the cumulative effect of multiple severe weather events and anthropogenic threats over the past decade Proserpine may reduce the Reef’s resilience; in particular its ability Mackay to recover. 85;93;94;95;96;97 Changes in wind patterns and intensity may have implications for the resuspension of QLD Clermont. sediments in the Region; including those delivered from the catchment and those disposed of during dredging Rockhampton Gladstone activities.

It is predicted that ocean acidification could ultimately Bundaberg affect most marine life through habitat destruction or Maryborough modification; food web deterioration and disruption Gympie of physiological processes. 98 In addition; the effects SDC131114 52 24 Jun of global warming and ocean acidification may magnify each other99 and may not occur uniformly Figure 6.8 Cyclone wave exposure; 2001 For the Region; a significant wave height of four metres is likely to damage many from place to place and over time.100 Even relatively species.

In particular; because much of the land adjacent to the Great Barrier Reef is low lying; small changes in sea level will mean increased erosion and land inundation; causing significant changes in tidal habitats such as mangroves; and saltwater intrusion into low lying freshwater habitats.110; Brackish saltmarsh habitats are being displaced by mangroves. 112 Turtle and seabird nesting beaches; including on islands; are particularly vulnerable to rising sea levels; which exacerbate beach erosion113 and inundate nests As well as its direct effects on the Region’s ecosystem; climate change will also have indirect effects on the Reef’s resilience through amplifying the effects of other influencing factors such as coastal development and land based run off.

For example; flood events carry pulses of nutrients; sediments; pesticides and other pollutants from the catchment; which have significant effects on inshore Great Barrier Reef habitats and species.115 Extreme weather events such as those in 2010 11 result in large amounts of marine debris washing or blowing into the Region from the catchment. 116; Additionally; engineering solutions to improve the resistance of coastal assets to rising sea levels and increased storm intensities may interfere with the connectivity of coastal and marine systems or cause damage or loss of coastal habitats. 118;119; 6.3.3 Vulnerability of heritage values to climate change Section 6.3.2 has demonstrated the very high vulnerability of the Region’s ecosystem to climate change.

In many instances the relevant ecosystem values; and therefore the scientific heritage values associated with them; are likely to become significantly degraded through the effects of global warming and ocean acidification. 6.3.4 Implications of climate change for regional communities Many Australians are concerned about the Great Barrier Reef being damaged or threatened by climate change.25;129 Climate change is likely to affect the way people interact with the Region and the social and economic benefits they derive from it.

For example; foreshores and coastal infrastructure such as ports130; and the benefits communities derive from them; will be influenced by climate change impacts on the catchment and the Region.

The effects of climate change on coral reef ecosystems are predicted to be widespread and irreversible.

Therefore; climate change poses one of the greatest risks to the future economic value of Reef dependent industries such as tourism; fishing and recreation.

While the implications of climate change for the economic value of Reef dependent industries are numerous and there is an improved understanding of these91; they remain difficult to accurately quantify.

The tourism industry is very concerned about the impacts of climate change on its businesses and livelihoods; including through degradation of reef sites; poor recovery of bleached sites as a result of other stresses; and a loss of marketing appeal as a high quality reef destination.137 A healthy and resilient Reef is fundamental to the success of many tourism operations and deteriorating Reef conditions may reduce visitor satisfaction.

It is likely fishing activities will also be highly sensitive to climate change; including as a result of projected changes in fish abundance; survivorship 138;139;140; size and distribution; disruptions to shallow water nurseries and loss of coral reef habitats; as well as changes in cyclone and storm activity.72;141; Extreme weather events may provide a window into the future for predicting impacts of climate change stal communities; especially the flow on effects of major ecosystem disturbances.

The vulnerability of commercial fishers and tourism operators to climate change will depend on their exposure and sensitivity to the associated impacts; as well as the ability of the individuals or operators to anticipate and adapt to change. 93 Although severe weather events such as floods and higher intensity cyclones may interrupt Reef based businesses and decrease visitor satisfaction; the level of identity with; and attachment to the Great Barrier Reef by Reef based industry and community members is likely to remain high.144; WORDEN Damage to foreshores and coastal infrastructure affects people’s use of the Region 6.4 Coastal development Aboriginal people have lived along the coast of the Great Barrier Reef for over 40;000 years.

The continued use of fossil fuels globally is the major driver of climate and ocean change; and servicing the export of coal is the major driver of port expansion along the Region’s coast and population growth in the catchment.

Heavy rainfall events could become more frequent in future as the climate changes (Section 6.3.1)37.

The combined influence of the four factors Very low Low High high is concentrated in inshore central and southern areas. impact impact impact impact Grade Trends Climate change Climate change is predicted to continue to have far reaching consequences for the Reef ecosystem and over the next 50 years it is likely to significantly affect most components.

For built heritage; the Very threats from climate change and direct use are the most serious.

Very low Low High high impact impact impact impact Grade Trend Climate change The vulnerability of the ecosystem to climate change flows through to dependent heritage values; especially the Reef’s outstanding universal value; natural heritage values and Indigenous heritage values.

Very low impact Very Low High high impact impact impact Grade Trends Climate change Climate change effects on the ecosystem are expected to have major economic consequences for Reef dependent industries. 个 个 Coastal development An increasing coastal population and improved coastal infrastructure is likely to increase the economic worth of uses in the Region.

Very low impact Climate change Climate related changes to the ecosystem could affect patterns of use of the Great Barrier Reef and visitor satisfaction.

The projected; far reaching; impacts from climate change are likely to ultimately overshadow the effects of other factors and uses.

Climate change is already affecting the Region’s physical; ecological and social environment.

Climate change will drive global changes in ocean pH and prominent weather events and characteristics such as temperature; cyclones; heavy rainfall; droughts; and prevailing winds.

Recent cyclones; hot spells and high rainfall events have demonstrated the capacity that ongoing changes to the Region’s climate have to significantly affect ecosystem and heritage values.

In addition; climate change has implications for all the other influencing factors and their trends into the future.

The continuing increasing trends in climate change variables means that it is likely to be an increasingly important factor in the Region.

Overall; the weakest performance was for climate change; then coastal development; land based run off and fishing.

The projected vulnerability of coral reef habitats to changing climate variables (see Section 6.3.2); combined with other cumulative impacts; means coral reef habitats will face chronic effects plus more frequent and more severe disturbance events. 9;42;65;66;67 This will reduce their resilience. 15; Frequent disturbances and chronic stresses reduce the potential for reef recovery. 8.3.2 Lagoon floor habitats There is limited information on the condition of the lagoon floor (see Section 2.3.6); although it is reasonable to assume that it varies considerably across the Region.

Under climate change projections; sea temperatures will continue to rise and the frequency of coral bleaching events and the intensity of storms are expected to increase (see Section 6.3.1).

Current evidence suggests climate change trajectories remain on course for increasingly serious impacts in the Region.

As these effects worsen; it is very likely that interactions between climate related threats and other threats will have increasingly serious consequences.

The most serious risks arise from climate change; land based run off; coastal development and some aspects of direct use (particularly fishing).

As a result; the most serious risks to the Region’s heritage values are similarly climate change; land based run off; coastal development and some aspects of direct use.

While climate change will affect all parts of the Great Barrier Reef; the compounding effects of threats associated with catchment runoff; coastal development and some extractive use means that the nearshore environment next to developed areas is the most at risk.

The risks associated with a changing climate are likely to increase in the future due to emissions trajectories and an unavoidable lag effect where future change is locked in by past emissions.

Overall risk associated with climate change and land based run off has remained very high and high; respectively; since 2009.

The most serious risks arise from climate change; land based run off; coastal development and some aspects of direct use (particularly fishing).

As a result; the most serious risks to the Region’s heritage values are similarly climate change; land based run off; coastal development and some aspects of direct use.

The greatest long term threats facing the Great Barrier Reef ecosystem are from climate change.

For all the Region’s values; threats associated with rising levels of greenhouse gases in the atmosphere such as ocean acidification; increased sea temperatures and rising sea level are likely to become more severe into the future.

The most serious threats are from climate change; land based run off; coastal development and some aspects of direct use such as illegal fishing and poaching and the incidental take of species of conservation concern.

Some threats are increasing; driven mainly by climate change; economic growth and population growth.

The extent and persistence of the damage will depend to a large degree on the extent to which climate change is addressed worldwide and on the resilience of the ecosystem in the immediate future.

Many ecosystem components are already showing some effects from climate change (for example increased frequency and severity of coral bleaching and decreased density of coral structures).

It is only with atmospheric concentrations of carbon dioxide between current levels and about 400ppm that the key groups of species and habitats of the Great Barrier Reef have low or moderate vulnerability to climate change.

For some of the threats related to climate change; southern areas of the Great Barrier Reef Region; especially inshore; are predicted to be the most vulnerable.

Climate change As well as indirectly driving change in factors that influence the Reef; climate change will directly influence the Region and continue to have far reaching consequences.

As the effects of climate change worsen; it is likely that interactions between climate related threats and other threats will have increasingly serious consequences.

Islands are also considered vulnerable to climate change.25;30; 2.3.2 Mainland beaches and coastlines Some beaches and coastlines have been modified especially around urban centres and ports.

Altered weather patterns A number of weather aspects are predicted to change as a result of climate change; including the frequency and intensity of cyclones; wind patterns; droughts and floods.

For example; cyclones; a natural process in tropical regions; are predicted to become more severe; but less frequent; under current climate change scenarios.

Regardless of the variation in climate scenarios; it is predicted that by 2035 the average sea surface temperature will be warmer than any previously recorded.

Altered weather patterns A number of weather aspects are predicted to change as a result of climate change.

Very good Good Poor Very poor Grade Trend Islands Some islands have been affected by recent extreme weather; invasive pests and weeds; marine debris; climate change and coastal development Mainland beaches and coastlines Some mainland beaches and coastlines have been modified especially around urban centres and ports.

Further changes in processes such as sea temperature; sea level; cyclones and wind; freshwater inflow; waves and currents are expected under climate change projections.

Ocean pH is changing and is projected to decline in the future under climate change scenarios.

Sea temperatures are increasing because of climate change; leading to mass bleaching of corals and increasing ocean acidity is affecting rates of calcification.

Severe bleaching events are linked to climate phenomena such as El Niño Southern Oscillation which results in sustained elevated regional temperatures.

Bundaberg Maryborough N Gympie 3.3.2 Ocean pH Kilometres SDC131114 51 04 Mar It is estimated that an increase in the amount of carbon dioxide absorbed by the ocean has already caused a decrease in global ocean acidity of 0.1 pH units compared to the long term average. 101;102 From a current pH of 8.1102; it is predicted that the ocean could fall to a pH of about 7.6 by 2100; with slight regional variation.

Decreasing ocean pH has an increasing negative effect on the calcification process and thus progressively slows the process of reef building.101;174;177 However; the impact varies between coral species as well as between organisms.178 The predicted concurrent warming of the oceans speeds up the calcification process potentially counteracting to some extent the negative effects of decreasing ocean pH at some reefs.179 In addition; ocean chemistry fluctuates greatly at small scales across a reef; and corals are capable of modifying their seawater carbon chemistry; thus potentially negating some of the possible large scale impacts of climate change on this reef building.

Coral disease is being increasingly observed on the Great Barrier Reef and is predicted to increase in the future. 233;234 Major outbreaks of the naturally occurring white syndrome disease have been recorded after especially warm years on reefs with high coral cover; indicating a potential link between coral disease and increasing sea temperatures as a result of climate change.230;233;235;236 More recently; coral disease has also been linked to cooler than normal conditions.

Further changes in factors such as sea temperature; sea level and sedimentation are expected because of climate change and catchment runoff.

Further changes in processes such as sea temperature; sea level; cyclones and wind; freshwater inflow; waves and currents are expected under climate change projections.

Ocean pH is changing and is projected to decline in the future under climate change scenarios.

Nevertheless; extreme weather events; combined with the lag times required for the recovery of key habitats; species and ecosystem processes; have caused the continued deterioration of the overall health of the Great Barrier Reef.

Sea temperatures are on the rise and this trend is expected to continue; leading to an increased risk of mass coral bleaching gradual ocean acidification will increasingly restrict coral growth and survival and there are likely to be more intense weather events.

The impacts of increasing ocean temperatures and ocean acidification will be amplified by the accumulation of other impacts such as those caused by excess nutrient run off. vi Large areas of the Region continue to be exposed to elevated concentrations of suspended sediments; excess nutrients and pesticides; which are significantly affecting inshore areas along the developed coast.

Climate change is escalating and is the most significant threat to the Region’s long term outlook.

Significant global action to address climate change is critical to slowing deterioration of the Reef’s ecosystem and heritage values and supporting recovery.

Given the global scale of human induced climate change; the size of the property is becoming a less effective buffer to broadscale and cumulative impacts.

Of the very high risk threats; most relate to climate change or land based run off (water quality) affecting values on a Region wide scale.

Without additional local; national and global action on the greatest threats; the overall outlook for the Great Barrier Reef’s ecosystem will remain very poor; with continuing consequences for its heritage values also.

However; since 2014; the condition of one of the most critical physical processes; sea temperature; has deteriorated to very poor condition across a wide area as a result of climate change.

The habitat and species condition grades reflect the increasing cumulative pressures the Region faces from a changing climate and other anthropogenic impacts.

Climate change remains the greatest risk to the outstanding universal value of the World Heritage Area and its integrity.

Given its Gladstone Lady Elliot Island location; more frequent intense storms predicted Bustard Head under climate change scenarios; could affect Bundaberg the historic and Indigenous heritage value Maryborough of the place.

The Shoalwater Bay Military Training Area Commonwealth heritage place will; therefore; be affected by drivers and pressures; such as climate change and anthropogenic threats.

Components of natural phenomena; such as turtle breeding; whale migration and coral spawning; continue but these elements (criterion vii) are being increasingly challenged by climate change; resulting in the condition being good borderline poor.

This alteration is intensifying in a negative way due to climate change (criterion viii).

However; many ecological processes have deteriorated since 2014 due to the combined effects of climate change and inshore land based run off.

An altered disturbance regime due to climate change has impaired the resilience of the ecosystem resulting in the condition being good borderline poor.

The Reef is currently undergoing significant social; economic and environmental change. 969 Drivers affect how society functions and interacts with the built and natural environment; and can act independently or in combination. 1011 Economic and population growth; technological developments and societal attitudes are key drivers and affect the nature and intensity of the four primary factors influencing the Region (climate change; coastal development; land based run off and direct use) (Figure 6.1).

Climate change Climate change due to human activities is a global issue that affects terrestrial; wetland; freshwater; marine and coastal ecosystems and the services they provide.

Climate change is the most pervasive and persistent influence on the Region.

The most immediate and priority current threat from climate change is thermal extremes that cause mass mortality of corals and other organisms.

Effects from sea level rise and ocean acidification are slowly increasing; but are not having nearly the same immediate and Region wide Great Barrier Reef waters have impact as increases in sea temperature. already warmed by more than In 2016 and 2017; the Region underwent two consecutive summers of mass coral 0.8 degrees Celsius since 1880 due to anthropogenic bleaching; resulting in the loss of at least 30 per cent of the Region’s shallow water climate change; with severe coral cover (Section 2.3.5).

These events are directly attributed to warmer than average impacts already being sea temperatures due to climate change. 1139 The present day frequency and severity of observed in the Region climate change related impacts are increasing and interacting with the other key threats (Sections 6.4 to 6.6); compounding their effects.

In the past four years; many worst case scenario climate change predictions made over years ago 1140 have now been realised141; and our understanding of the future conditions of ecosystems in the Region has grown considerably. 6.3.1 Trends in climate change Human activities have already caused approximately one degree Celsius of global warming above pre industrial levels; with a likely range of 0.8 degrees Celsius to 1.2 degrees Celsius. 1141 Warming is generally higher over land than over the ocean; but recent evidence suggests oceans are heating up about 40 per cent faster than previously estimated502 and the pace of change is accelerating at an unprecedented rate452 (Figure 6.4).

Both the magnitude and rate of these changes exceed the extent of natural variation over the last millennium and over glacial interglacial time scales. 1142;1143;1144 The extent to which the climate will change in coming decades depends on current and future greenhouse gas emissions.

Both global carbon dioxide concentrations (left) and the annual mean carbon dioxide rate of increase (right) rose steadily between 1959 and mid 2018.

The dotted lines represent the Australian equivalent of a marine heatwave occurring in any given year will be double of the global warming thresholds of 1.5 C and 2 C above that of today; if warming reaches 1.5 degrees Celsius and triple if preindustrial levels; which are used to inform possible risks warming reaches two degrees Celsius. and responses for coming decades.

For example; it is estimated that by 2090 under the worst case scenario (RCP 8.5); Cairns would experience 48 days per year of air temperatures exceeding 35 degrees Celsius; a dramatic rise from the current three days per year. 485;1156 The frequency and severity of extreme events; such as heat waves; are Heatwaves are becoming critical and have important consequences for the Region’s values. hotter; lasting longer and occurring more often; As the ocean continues to warm and land based ice starts to melt; the pace of global affecting both terrestrial and sea level rise will accelerate.485 Although mitigation of greenhouse gas emissions might marine environments reduce the overall magnitude of sea level rise in the long term; the Earth is already locked into significant sea level rise this century; regardless of what future emission scenario is followed; due to the lag effects in ocean warming and ice melt. 1157;1158 Projections for global sea level rise by 2090 range from 0.6 to 0.86 metres and strongly depend on current and future emissions.

The increase in carbon dioxide has also reduced the concentration of carbonate ions in the ocean by 30 per cent545;1162 at a rate at least 10 times faster than any concentration Rockhampton change within the last 65 million years 1163; Gladstone In the Region; the rate and magnitude of increases Bundaberg of carbon dioxide concentrations are more significant QLD on inshore reefs (those within 10 kilometres of the coast) than reefs further offshore. 162; 163; 164 In the past 30 years; carbon dioxide concentrations on these inshore reefs have increased at a rate up to three times higher than atmospheric values; suggesting Figure 6.6 Average warming of annual sea surface temperature between 1880 and 2018 for the Great Barrier Reef that the Region’s inshore coral reefs are more Annual sea surface temperature (SST) was extracted from the Met Office vulnerable to ocean acidification and have less Hadley Centre for Climate Prediction and Research (HadISST1 data set) for buffering capacity compared to mid and outer shelf 1 degree latitude x 1 degree longitude grid boxes for the Region. reefs. 162 However; the effects of this may currently be Source Rayner et al. negligible compared to the observed; severe impact of ocean warming on the Reef.

The major current in the Region; the East Australian Current; has become one of the fastest warming currents in the world; warming two to three times faster than the global average ocean warming rate.427 This has led to two major changes in the current’s properties the amount of water it transports southward and the frequency of eddy formation.

As a result; a marked increase in the frequency of the most intense cyclones (categories 4 and 5) is projected. 1164;1166;1167 Since 1975; the proportion of intense tropical cyclones has increased 25 30 per cent; corresponding to the observed one degree Celsius of global warming. . 1167 Modelled projections have indicated that relative to pre industrial conditions; cyclones in northeast Australia will have both higher wind speeds (by 5 10 per cent on average) and heavier rainfall (by up to 27 per cent for average hourly rainfall rates) under worst case scenario (RCP 8.5) future climate change. 1168 To date; climate change has not significantly influenced cyclone wind speeds but has significantly enhanced rainfall by 4 9 per cent. 1169 The forward speed of tropical cyclones over Australia has slowed by 22 per cent since 1946; increasing the potential higher total rainfalls as cyclones remain over certain locations for longer periods.

Rainfall variability is strongly related to changes in sea surface temperatures across the Pacific Ocean associated with El Niño Southern Oscillation. 1170 However; as the influence of climate change strengthens; the intensity of heavy rainfall events is projected to increase in the Region. 1156 This has already occurred on a global scale approximately 20 per cent of global heavy rainfall events over land are attributable to the observed temperature increase since pre industrial times. 1171 Australian weather station records show that a higher proportion of total annual rainfall in recent decades; compared with earlier; has come from heavy rain days. 452 For heavy rain days; total rainfall is expected to increase by around seven per cent for each degree of warming; whereas for short duration rainfall events; observations in Australia generally show a larger than seven per cent increase per degree of warming. 452 More intense rainfall will increase the likelihood of severe floods and subsequent large freshwater inflows to the marine environment (Section 3.2.3); increasing turbidity and sedimentation (Section 3.2.4) that can damage inshore coral reefs and seagrass meadows.

Extreme El Niño events have occurred in the Region in 1982 83; 1997 98 and 2015 16 coinciding with worldwide climate extremes and are predicted to increase in frequency due to climate change. 1173 Compared to the past four centuries; Eastern Pacific El Niño events over the last 30 years have been fewer; but more intense. 1174 Additionally; the link between El Niño and coral bleaching has weakened; because La Niña sea surface temperatures today are warmer than they were during El Niños 30 years ago; due to global heating. 99 Two of the four mass bleaching events on the Reef have occurred during El Niño phases of El Niño Southern Oscillation cycles (1998 and 2016) and two have not (2002 and 2017).88 Even if global warming is limited to 1.5 degrees Celsius; the risk of extreme El Niño events is predicted to increase from around five events per 100 years to at least 10 events per 100 years by 2050 (based on the lowest emissions scenario RCP2.6).1172 During extreme La Niña events; the Australian summer monsoon is more vigorous than usual; with more tropical cyclone activity in the Region.

Cascading effects have already resulted in the decline of habitats in the Region coral associated fish and invertebrates.244;273 As the climate continues to change; the capacity of hard corals to survive; grow and reproduce is increasingly compromisedº; with resulting consequences for other species dependent on coral reefs (Section 2.3.5).

Seagrass meadows are less vulnerable to temperature increases than are coral reefs (Figure 6.7). 1181;1182 However; extreme water temperatures (greater than 40 degrees Celsius) can be fatal to seagrasses. 1181;1183 Recent evidence has linked seagrass decline in Western Australia more than 7400 hectares of mangrove dieback in the Gulf of Carpentaria1185 to severe marine heatwaves due to global warming.

Increases in temperature affect their performance and fitness. 1197;1198 Temperature impacts due to global warming are evident on many species in the Region (Section 2.4); with mass mortality of fish and invertebrates in shallow northern reef lagoons in 2016.

However; climate change is exacerbating both acute and chronic disturbances in the Region; shrinking recovery windows and overwhelming resilience capability. 99;439;1152;1172 In the past four decades; warming due to climate change has resulted in a five fold increase in severe coral bleaching events globally99; and it will amplify the effects of other influencing factors; such as direct use; coastal development and land based run off (Sections 6.4 and 6.5). s 6.3.3 Implications of climate change for regional communities Climate change is the primary driver increasing threats to communities living in; or adjacent to; the Region; through an increase in climate extremes (record breaking temperatures; floods and droughts) and declining Reef condition.

Secondly; continued global use of fossil fuels is the primary driver of climate change and ocean warming (Section 6.3).

Global plastic use has increased twenty fold since the 1960s and is expected to double again in the next years 1274; so the potential for global environmental harm is significant.

Marine debris is a threatening process for wildlife 1096 and an emerging threat to the Region as the global human population increases (Section 6.2.1).

Dugong and green turtle populations are still depleted following past commercial harvesting and are further threatened by climate change.

Climate change; habitat loss and delayed recovery of critical fisheries habitats make the ecosystem more vulnerable to direct effects from fishing and other direct use.

FACTORS INFLUENCING THE REGION’S VALUES 6.7 Vulnerability of heritage values to influencing factors Of the four main factors influencing the Region (climate change; coastal development; land based run off and direct use); climate change remains the greatest threat to the Region’s heritage values.

Some traditionally valued species (marine turtles and dugong) remain under pressure from climate change; habitat loss and degradation; fishing associated impacts811; and marine debris.

Poor water quality; coupled with climate change impacts; natural processes and encroaching coastal development (ports; marinas; revetment walls) will place pressure on inshore and coastal natural and Indigenous heritage values.

Overall; a changing climate is imposing strong current and predicted impacts on all the Region’s heritage values.

Negative impacts on ecological values; associated with coastal development; land based run off and direct use are being amplified under the strong signal of climate change.

Climate change Climate change has had far reaching effects on the Reef; with record breaking sea surface temperatures resulting in widespread mortality of shallow water corals.

Impacts of climate change are becoming more severe and widespread.

More frequent acute disturbances (cyclones; flood plumes; coral bleaching) will exert more pressure on a degraded system. | 6.8.2 Impacts on heritage values Grade and trend Confidence Criterion and component summaries Grade Trend 个 个 Impact on heritage values The Region’s natural heritage value is already impacted by climate change; transforming the reefscape through reductions in species and habitats and altered ecological processes.

Historic heritage values remain vulnerable to a changing climate and impacts from human interaction.

Climate change The interconnectedness of the natural and Indigenous heritage values exacerbates the vulnerability of the Region to the impacts of a changing climate.

Altered weather patterns resulting from increased global emissions are a major threat to heritage values.

A changing climate is imposing strong current and predicted impacts on natural and Indigenous heritage values.

Of the four major factors; climate change is having the greatest impact on the Region’s values; and the signals of climate change; such as increasing water temperatures; are accelerating.

Furthermore; climate change will amplify the impacts of other threats.

The impacts of climate change will become more frequent; severe and widespread.

The resultant trend is one of increasing cumulative effects on Overwhelmingly; climate the Region’s ecological; heritage; economic and social values.

The impact of climate change (causing unprecedented mass mortality of corals in 2016 and 2017); poor water quality and severe weather on particular tourism sites; has increased dramatically since 2014.

The direct impacts of further climate change (Section 6.3.2); combined with chronic stressors; will further reduce reef resilience and deplete coral associated species. 99;141;501 Because of the increase in the frequency and intensity of disturbances; ecosystem resilience may already be on an irreversible path of decline. 96;99 These impacts have serious implications for Reef dependent industries and community benefits. 8.3.2 Lagoon floor habitats The lagoon floor is one of the most expansive habitats within the Region; and its condition is likely to vary spatially (Section 2.3.6).

Impacts associated with climate change; bottom trawling and dredging are known to pose the greatest risks to this habitat.109;110;111 The current and projected effects of climate change (Section 6.2); such as rising temperatures; thermal extremes and an increase in storm severity; directly threaten a broad suite of lagoonal species; such as sponges; corals and molluscs. .

Considering their high vulnerability to climate change and the recent record breaking temperatures in the Region 165; particularly during their winter spawning season; it is possible that black teatfish recovery may have been affected by thermal stress. 8.3.4 Coral trout Coral trout is the collective name for several species of coral reef associated; predatory fishes on the Reef.

The capacity of coral trout to resist disturbances in the future is decreasing due to two distinct effects of climate change the direct effects of environmental change (increasing sea temperature); and indirect effects of habitat degradation.

The Region’s lightstations are located on exposed islands within the Region; so their historic heritage value is highly vulnerable to the threats posed by climate change (Section 6.7).

The most serious risks arise from certain threats associated with climate change; land based run off; coastal development and some aspects of direct use (particularly fishing).

The most serious risks are climate change; land based run off; coastal development and some aspects of direct use.

Ecosystem The risk from climate change has continued to increase and the associated threats and their impacts are increasingly observed in the Region.

Risk is likely to increase in future due to emission trajectories and unavoidable future climate change; locked in by past and current emissions.

Overall risk to heritage values 个 Climate change 个 Heritage The threats to the ecosystem associated with climate change flow on to present a serious risk to heritage values; particularly intangible Indigenous values and the Great Barrier Reef World Heritage Area’s outstanding universal value.

The most serious threats are those associated with climate change; land based run off; coastal development and some aspects of direct use (including the remaining impacts of fishing).

Threats associated with climate change; such as increased sea temperatures; altered weather patterns; ocean acidification; and rising sea level; are expected to become increasingly severe in the future.

Heightened concerns exist for the future of loggerhead; hawksbill and northern green turtles; due to climate change and fishing pressures outside the Region.

The size of the World Heritage Area is becoming less effective as a buffer to disturbance; particularly against the broadscale impacts of climate change.

However; water quality targets are not being met; which is compounding the effects of climate change and slowing recovery of inshore ecosystems.

Reef resilience is being severely compromised by global warming; which has resulted in mass mortality of adult coral and subsequent 89 per cent decline in coral recruitment.

The threats affecting the Region’s ecosystem (natural heritage values) are increasing; compounding and expanding in scale they are driven strongly by climate change.

The most serious risks to the Region’s heritage value are from climate change; land based run off; coastal development and some aspects of direct use.

Safeguard measures to mitigate climate change are essential for the long term conservation of the ecosystem. contain habitats for Declines in key habitats have been more rapid and widespread than was evident in maintaining the most diverse fauna and flora characteristic the period 2009 to 2014.

External pressures from global drivers; such as climate change; remain the greatest threat to the World Heritage Area and be preserved other properties globally.

Also; human activities in the Region Halimeda and Catchment continue to affect biodiversity values; banks with areas of the Region adjacent to large human populations and significant agricultural use generally mid shelf under higher pressure. other non reef Halimeda shoals Climate change and climate extremes have been the primary causes of habitat deterioration since outer reef mesophotic reef shell 2014; adding to legacy and current impacts; such as pollutants in land based run off and an ongoing crown of thorns starfish outbreak.

Nonetheless; this remote area can be affected by cyclones and marine debris transported by currents. 42;43 Climate change impacts; including extreme weather events; increased erosion and changes in sea level; are affecting beaches and coastlines. 41 Whitehaven Beach was one of the sites most affected by cyclone Debbie Beaches and coastlines in 2017.35 Fallen trees and debris were removed by machinery; and 10;000 cubic metres of sand was shifted to reinstate the beach profile.35 There are knowledge gaps in relation provide significant natural resources and valuable to the current condition and trend of mainland beaches and coastlines due to limited ecosystem services monitoring across the Region.

Some mangrove forests will be negatively affected by the continuing intensification of El Niño with climate change and associated sea level fluctuations and temperature increases. 49 Shoreline retreat and erosion are occurring along the Queensland coast; with sea levels rising faster in the north than in the south.52 Although localised loss of mangrove forests has occurred; recovery has been observed and overall they remain in a stable condition.

Altered weather patterns A number of weather aspects are predicted to change as a result of climate change; including the frequency and intensity of cyclones; floods and heatwaves (acute events) and changes in wind patterns and average rainfall and temperatures (chronic effects).

For example; cyclones; a natural process in tropical regions; are predicted to become more severe; but less frequent; under current climate change scenarios.

The loss of seagrass meadows causes the releases of stored carbon; further contributing to global warming. 51;61 Overall; seagrass abundance has been positive; albeit with some variability across the Region.

Climate change; ocean warming; acidification and changes to water circulation patterns remain the main pressures affecting the future condition of Halimeda banks and the species that rely on them.

However; there are growing concerns for the future of loggerhead; hawksbill and the northern green turtle populations due to a number of external pressures; including climate change and overseas fishing morality (in Chile and Peru).

Illegal poaching; habitat loss and climate change are the main threats to crocodiles. 330;346;347 Coastal development encroaching on swamplands; mangroves and riverbanks threatens crocodile populations south of Cooktown.

The major migration route; known as the East Asian Australasian Flyway; is among the most highly threatened flyways in the world due to widespread declines in; and degradation of; habitat. 371;373;375 Climate change represents a significant threat to shorebirds; with increasing temperatures already causing earlier migration times376; changes to egg laying times; timing mismatches with food resources377;378 and loss of habitat379.

Although threats to individual whales while transiting through the Region include entanglements in nets; underwater noise and vessel strikes; the greatest threat to the population persistence of baleen whales is climate change and the related effect on their food sources outside the Region. 385;389;390;391 The increasing abundance of humpback whales and ships in the Region is likely to increase ship and vessel strikes (Section 5.8.3).

Corals Unprecedented mass coral bleaching due to global warming; outbreaks of crown of thorns starfish and cyclone

Position snapshot Climate change is the greatest threat to the Great Barrier Reef (the Reef) and coral reefs worldwide.

Further loss of coral is inevitable and can be minimised by limiting global temperature increase to the maximum extent possible.

If the current rate of greenhouse gas emissions continues; global average temperature will continue to increase rapidly.

This continuing and rapid increase in global temperature is causing sea temperature to increase; which also increases the likelihood of marine heatwaves.

Impact half a degree matters Climate related impacts on the Reef are already detectable.

Any additional increase in global average temperature will have further negative impacts on the Reef; with flow on effects for Reef dependent activities such as tourism; fishing; recreation and traditional use.

Even with immediate and strong action to reduce global emissions; increasing temperatures will continue to affect the Reef due to the greenhouse gas already in the atmosphere.

Coral reefs globally; including the Great Barrier Reef; are deteriorating from the impacts of climate change.

In summary Climate change is the greatest threat to the Great Barrier Reef.

Associated impacts from altered weather patterns such as more intense storms; tropical cyclones and flood events ocean acidification and rising sea level also damage coral reef ecosystems.

Overall THREATS Very High Threat Climate change; catchment runoff; coastal development; ports; shipping and fishing pose the most important threats to the long term conservation of the property.

The GBRMPA has developed factsheets to assist tourism operators to reduce their emissions and adapt to climate change.

While it is recognised that it is the inshore reefs which are the most affected due to anthropogenic use; at the same time increase in extreme weather events has caused major damage and decline in WH values of the property since inscription.

Chemical changes in oceanic waters Very High Threat Inside site Outside site Ocean warming and acidification of water cause decline in coral (coral bleaching; reduced growth rates and or skeletal density) and other habitats (changes in rainfall patterns and increased likelihood of flooding affecting seagrass; mangroves).

Loss and degradation of critical habitat of the marine megafauna fragmentation of dugong; turtle and dolphin populations through habitat loss and degradation reducing their resilience to other anthropogenic impacts and the impact of extreme weather events; such as floods and cyclones.

Severe weather events; such as cyclones will also increase.

Other pressures cannot be addressed at the site level; such as climate change; which is recognized as the greatest threat to the Outstanding Universal Value of the site.

Collectively the various impacts of climate change pose the greatest current threat to the GBR; and both local and global efforts are urgently required to reduce those impacts.

Ocean acidification; Temperature extremes; Storms Flooding (Climate change and severe weather) Very High Threat Inside site; throughout( 50 ) Outside site Climate change poses the biggest threat to the long term conservation of the Great Barrier Reef and its Outstanding Universal Value (GBRMPA; 2019a).

Impacts of climate change are predicted to further accelerate in the future.

Climate change continues to have negative impacts on some critical processes; such as reef building and recruitment (GBRMPA; 2019a).

Other inverterbrate species are also being impacted by climate change.

The integrity of many important processes underpinning the complexity of the Great Barrier Reef has also been declining; as a result of climate change combined with other factors; including reef building and recruitment; with coral recruitment across the entire Great Barrier Reef estimated to have declined by 89 per cent in 2018 compared to recruitment levels before 2016.

Of most concern are ocean warming and acidification and the increased frequency and intensity of extreme weather events.

Severe weather events; such as cyclones are also predicted to increase in their intensity.

The combination of severe weather events in 2011 has also increased dugong mortality with evidence suggesting that large numbers of animals moved to the northern GBR as a result of the seagrass loss (UNESCO and IUCN; 2012).

The greatest threat to the Reef is climate change; with the other main threats being land based run off; coastal development and direct human use; such as illegal fishing and bycatch (Figure 4).

Global warming; and the climate change it drives; is the most serious and pervasive threat to the Reef a threat in common with all coral reefs globally.

Extreme temperature events contributed to by global warming are increasing in frequency and severity.

Coral reefs are projected to decline by a further 70 to 90 this century at global temperatures of 1.5 C above pre industrial levels; with even larger losses at global temperatures of 2 C above pre industrial levels (IPCC 2018).

The Director of the UNESCO World Heritage Centre has stated that most World Heritage listed coral reef sites may be lost if global temperature increase cannot be limited to 1.5 C above pre industrial levels (Rössler 2020; p. 5).

The biggest threat to the health of the Reef is global warming and subsequent climate change.

Changing weather patterns; sea level rise and altered ocean conditions also affect the land; species and people through coastal erosion and habitat inundation for example; in marine turtle nesting sites; causing hatchlings to die.

It highlighted that there are risks to the long term outlook of the GBR from climate change; declining water quality; coastal development and its impact on coastal ecosystems and some residual fishing activities.

Scientists predict impacts on these species under future climate change projections.

Increased temperature is; however; just one of many effects of climate change on the GBR.

These pollutants contribute to algal blooms; smothering of seagrass and overall make the GBR less resilient to other pressures such as climate change.

Extreme weather impacts For the last nine summers the GBR has not been widely impacted by mass bleaching events (the most recent severe bleaching occurred in 2001 02); but major impacts have occurred in recent years due to severe floods and destructive cyclones.

The 2011 flooding has been a further reminder of how much sediment; nutrients and pesticides are delivered to the GBR from agriculture during flood events and the impact that has on seagrass health and the health of those animals that rely on good quality habitat such as dugong and turtles.

A key challenge facing the GBR is that climate change and other pressures are likely to amplify these natural fluctuations; although the magnitude of these effects is subject to considerable uncertainty.

Climate change is predicted to increase the intensity and frequency of extreme weather events; such as cyclones and storms.

Nonetheless; the Australian Government recognises the link between climate change and increased carbon emissions and has committed to a long term target for carbon pollution reduction of 80 per cent below 2000 levels by 2050.

A consensus statement on Climate Change and Coral Reefs highlighted the grave threat that climate change poses globally to all coral reefs and called on governments to act to address both the causes of climate change and to improve local protection of coral reefs worldwide.

Coral reefs globally are highly vulnerable to the impacts of future climate change; including coral bleaching and other effects of increased temperature; and ocean acidification.

These include declining water quality due to catchment run off; loss of habitat due to coastal and port development and climate change; and loss of connectivity through fragmentation and modification of ecosystems.

Many of the factors that impact on the GBR occur naturally; including weather events such as storms and cyclones coral bleaching run off of fresh water from land to sea following heavy rainfall and predators; such as the crown of thorns starfish.

Extreme weather events can cause very severe damage and reduce the time available for the reef to recover.

There is strong evidence that nutrient rich flood waters arising from the extreme weather events of 2009 to 2011 have created conditions that result in increased numbers of the crown of thorns starfish; which preys on coral.

O Crown of thorns starfish There is strong evidence that poor water quality resulting from floods and extreme weather events in the summers of 2009 to 2011 have created conditions which have resulted in crown of thorns starfish numbers increasing at some locations in the GBR.

Much of the mortality is associated with starvation following depleted sea grass in the wake of extreme weather events.

No calves were seen in the surveys during the surveys indicating a reduction in fertility in response to the extreme weather in 2011 which exacerbated a decline in their seagrass feeding grounds over several years.

Climate change is predicted to increase the intensity of extreme weather events. 4.

Climate change was found to be the most concerning pressure.

Ribbon reefs; deltaic reefs and northern detached reefs were identified as being the most sensitive and at risk to climate change; with their location on the continental shelf exposing them to high energy impacts from extreme weather.

It showed that climate change and storms are likely to be the key stressors affecting reef and seagrass ecosystems in the future.

The food plume extent for 2010 11 (brown line) indicates the distribution of the flood plume as a result of the extreme weather events experienced over that summer.

This extreme weather caused flooding in several catchments and much higher than normal discharge from most rivers.

Photo Daniel Schultz There is emerging evidence that poor water quality resulting from floods and extreme weather events in the summers of 2009 to 2011 have created conditions for crown of thorns starfish numbers to increase at some locations on the Great Barrier Reef.

Box 2 Dugong and green turtle mortality recovers from impacts of floods Over the last five years; predominant La Niña weather patterns led to extreme floods and storms that affected coastal water quality and seagrasses along some 1500 kilometres of the southern two thirds of the Great Barrier Reef Region. (Left) Dugong (Dugong dugon) feeding on seagrass.

Recent extreme weather events; nts heavy rainfall; floods and tropical cyclones have severely impacted marine water quality and Great Barrier Reef ecosystems.

The impact of severe weather events such as Yasi on the health of the Reef reinforces the need to strengthen its resilience by controlling the impacts from land based activities.

It is expected to show a slight improvement in marine water quality condition due to the abatement of extreme weather in the last two years (2011 2013).

While nesting habitats are site at Raine Island; the generally in good condition; sea level rise; increasing air temperature and Great Barrier Reef also includes many regionally extreme weather events are affecting their condition. important marine turtle rookeries Some 242 species of birds have been recorded in the Great While the nesting habitats for seabirds Barrier Reef.

The framework can use quantitative data (for example on flood plumes) to identify spatial zones of influence where impacts are expected to have a significant and observable pressure on Great Barrier Reef ecosystems; and where these impacts overlap.

Climate change is the most significant threat to coral reefs worldwide.

Further information on Australia’s domestic and international response to climate change; including Australia’s commitment of 2.55 billion to an Emissions Reduction Fund and its pledge of 200 million to the Green Climate Fund; is included in Section 3.1.

Ocean acidification; sea temperature increases; altered weather patterns (such as more intense storms) and rising sea levels all threaten the Reef.

While nesting habitats are generally in good condition; sea level rise; increasing air temperature and extreme weather events are affecting their condition.

Climate change is foremost among the pressures facing the Reef.

It states that climate change (especially sea temperature rise) remains the most serious and pervasive threat to the Great Barrier Reef a threat in common with all coral reefs globally.

Climate change; poor water quality caused primarily by land based run off; coastal development and some aspects of direct human use such as illegal fishing are the primary threats.

Among them; climate change is the most significant and can only be addressed by effective global action under the Paris Agreement.

Climate change (especially sea temperature rise and temperature extremes) remains the most serious and pervasive threat to the Reef a threat in common with all coral reefs globally.

It concluded that the long term outlook for the Reef’s ecosystem has deteriorated from poor to very poor and indicated that accelerated action to mitigate climate change and improve water quality is essential to turn around this outlook.

However; climate change is having a detrimental impact on some critical regulating processes such as sea temperature; reef building and recruitment (the addition of new young to the population) which means the ability of the system to bounce back is weakening. 4.

Global warming and the climate change it drives is the most serious and pervasive threat to the Reef.

Climate change impacts are being amplified by other threats including land based run off from agricultural; urban and industrial sources.

Increasing temperatures are Global warming and the climate change it drives is the threatening most species and most serious and pervasive threat to the Reef a threat habitats in the Reef ecosystem. in common with all coral reefs globally.

Extreme temperature The greatest water quality risks to events driven by global warming are increasing in the Reef and its coastal frequency and severity and have already caused ecosystems are land derived inputs significant mortality in corals and other species (including from nutrients; fine sediments and fish and invertebrates).

Marine debris can be eaten by Global warming from greenhouse gases is also changing wildlife or entangle them; impacting weather patterns and altering ocean currents.

Climate change is the most serious and pervasive threat to the Reef.

These climate change impacts are being amplified by other threats including land based run off from agricultural; urban and industrial sources.

Events such as floods and cyclones; along with changes in physical processes such as increasing sea temperature caused by global warming; have resulted in limited progress against some ecosystem health targets under the Reef 2050 Plan.

Case Study National Environmental Science Program Climate change; poor water quality from land based run off; impacts from coastal development and some fishing impacts such as illegal fishing are the major challenges being tackled as part of the National Environmental Science Program.

The number of reef dependent industries with low climate risk vulnerability ratings is increased.

Changing weather patterns and altered ocean currents then affect the land; species and people through coastal erosion and inundation of habitats for example; turtle nesting sites; causing mortality of hatchlings. areas.

They are threatened by sea level rise; coastal erosion; severe weather (including cyclones and wildfires); marine debris and invasive species (GBRMPA 2019a).