What the science tell us

Scientific and experiential evidence of the accelerating risks of climate change trends and impacts is powerful and compelling.

Climate change is impacting the world today and, without stronger efforts to curb emissions, more damaging impacts are predicted.

Climate change is already having damaging and increasing impacts on Australian ecosystems, communities and the economy. Global climate risks are already increasing at an alarming rate.

According to CSIRO and the Bureau of Meteorology, Australia’s climate has warmed in both mean surface air temperature and surrounding sea surface temperature by around 1°C since 1910.

Extreme heat-related events

  • Climate change trends indicate the duration, frequency and intensity of extreme heat events have increased across large parts of Australia.
  • There has been an increase in extreme fire weather, and a longer fire season, across large parts of Australia since the 1970s.

Rainfall, floods and oceans

  • May–July rainfall has reduced by around 19 per cent since 1970 in the south west of Australia.
  • The April-October growing season rainfall in the south east of Australia has declined by around 11 per cent since the mid-1990s.
  • Rainfall has increased across parts of northern Australia since the 1970s.
  • Oceans around Australia are warming and ocean acidity levels have increased.
  • Sea levels have risen around Australia. The rise in mean sea level amplifies the effects of high tides and storm surges.
  • These conclusions are consistent with the findings of the Australia State of the Environment 2016 (SoE) report.

2017 annual climate facts and events

State if the environment
Overview of major Australian climate related trends and events in 2017
Source: Australian Bureau of Meteorology

International climate change trends

The Australian experience of climate change is part of a global picture. The 2014 Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) concluded that:

Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia.

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

Nasa data
Atmospheric carbon dioxide levels over last 400,000 years
Source: NASA

The current warming trend is of particular significance because most of it is extremely likely (greater than 95 per cent probability) to be the result of human activity since the mid-20th century and proceeding at a rate that is unprecedented over decades to millennia.

NASA 2017

Global CO2 concentrations in Earth’s atmosphere have risen from 280 parts per million (ppm) in 1780 (the beginning of the industrial revolution) to 316 ppm in 1958 (when first consistently measured at the Mauna Loa Observatory in Hawaii) to over 408 ppm in January 2018.

The last time global CO2 concentrations were above 400 ppm was over 3 million years ago. Global temperatures at that time were 3 to 4°C warmer than they are now (and over 10°C warmer at the poles). Sea levels were over 15 metres higher than they are now.

Earth’s average surface temperature has risen by about 1.1°C since the late 19th Century. Most of this warming has occurred since 1980. 16 of the 17 warmest years on record have occurred since 2001. Five of the warmest years on record have taken place since 2010. 2016 was the warmest year on record. 2017 was the third warmest year on record.

Climate change trends and projections for future risks

Climate change trends from modelling scenarios in the most recent (2014) IPCC Fifth Assessment Report indicate a range of likely increases in global surface temperature by 2100 from over 4°C at the highest end (if emissions continue to increase at the rate at which they have over the last 35 years) to 1.5°C at the lowest end (if there is extremely early and rapid action taken to reduce emissions). The 1.5°C outcome would require emission reductions and carbon drawdown at a far more ambitious speed and scale than the current Paris Agreement commitments.

Climate tracker
2100 Global warming trends and projections, 1990-2100
Source: Climate Action Tracker

Noting that policies being implemented by many countries are not yet fully consistent with national pledges and bearing in mind the recent withdrawal of the USA from the Paris Agreement, Climate Action Tracker modelling estimates the range of global warming outcomes from successful implementation of current national climate policies in a range from 2.5 to 4.7°C with a median outcome of 3.4°C. A wide range of other leading international climate science and energy research organisations have reached similar conclusions. The most recent analysis of the global carbon budget (the amount of carbon which can be released in order have a reasonable chance of keeping global temperatures below 2°C) provides a different, equally compelling way of understanding the challenges ahead. The 2017 Global Carbon Budget report confirms that annual global emissions are still tracking well above the level needed to achieve the goal of net zero emissions no later than 2040.

While there is widespread agreement that current national climate pledges and policy commitments fall well short of the actions required to achieve the Paris Agreement targets, a number of recent research studies highlight the need to carefully consider the possibility of even higher levels of climate change risk.

One major cause of concern is the increasingly strong evidence that the full extent of global warming is being masked (probably by about 0.9°C) by the presence in the atmosphere of aerosols such as sulphates, nitrates and dust. As necessary and decisive action is taken to reduce these air pollutants (which currently cause over 7 million deaths per year), the rate of global warming is likely to accelerate.

INDC Temp Analysis
Estimates for global temperature rises with NDCs.
Source: World Resources Institute

Yangyang Xua and Veerabhadran Ramanathan (climate science adviser to the Vatican) also highlight the need to pay close attention to the consequences of low probability/high impact global warming scenarios. In reflecting on their conclusions indicating a 5 per cent chance that global temperatures could rise by as much as 6.5-8.0°C by 2100, we need to carefully consider the confronting question: Would we get on a plane or a train which had such a high probability of crashing?

Even if we ignore the fact that 2100 is now well within the lifespan of children already alive – and certainly of our grandchildren – likely global temperature increases for far shorter periods of time also create significant risks. Modelling by the UK Met Office and Climate Action Tracker indicates that global temperatures are likely to exceed 1.5°C in the next decade. The study by Xua and Ramanathan points to a 5 per cent chance of a 3.5-4.0°C temperature increase by 2050.

The landmark study, ‘Trajectories of the Earth System in the Anthropocene’ (Proceedings of the National Academy of Science, 1 August 2018) analysed a wide range of climate tipping points leading to the conclusion that there is a very real chance that the Earth is heading towards a “hothouse climate”. This could lead to average temperatures up to 5°C higher than pre-industrial temperatures and rises in sea level of between 10 and 60 metres.

Importantly this paper also identified an extensive range of urgent actions which need to be taken in order to reduce the likelihood of triggering “hothouse climate” tipping points.

Climate change will result in location-specific vulnerabilities.

Australia is predicted to experience increased heatwaves, leading to increased bush fire incidence and health problems (heat stress); longer droughts, extending further geographically; flooding from more intense storm activity; sea level rise, leading to coastal damage; and loss of ecosystems.

The 2016 bleaching of the Great Barrier Reef demonstrates how vulnerable Australian ecosystems are to climate change.

Future climate change trends

The Australia State of the Environment 2016 report makes the following predictions in relation to future climate trends for Australia.

  1. Australian temperatures are projected to increase with more extremely hot days and fewer extremely cool days.
  2. An increase in the number of days with weather conducive to fire in southern and eastern Australia.
  3. Extreme rainfall events are likely to increase in intensity by the end of the century across most of Australia.
  4. Decrease of winter and spring rainfall across southern continental Australia, with more time spent in drought.
  5. Fewer tropical cyclones will form in the southern hemisphere than are currently observed, but a higher proportion will be more intense, with ongoing large variability from decade to decade.
  6. Past and ongoing emissions commit us to further sea-level rise around Australia in coming decades, with ongoing sea-level rise.
  7. Oceans around Australia will become warmer and acidification will continue — with significant impacts on marine ecosystems.

How will climate change trends affect Australia?

Predictions for Australia

Predictions for Australia

Climate change is now a ‘global existential risk’ and a ‘direct threat to the security of Australia’.

Sherri Goodman, former US Under Secretary of Defence

Australian climate change risks are likely to further increase and intensify as global temperatures continue to rise. As the driest inhabited continent on Earth with a highly variable climate, Australia’s natural ecosystems, cities and regional communities are all extremely vulnerable to even relatively low rises in temperature. Key risks from projected changes in the Australian climate include the following.

Heatwaves, fire and drought

A warming and drying climate with increased incidence of heatwaves is projected to lead to an increase in extreme fire-danger days and bush fires in South Eastern Australia. Increased frequency and severity of heatwaves will to lead to a significant increase in health risks. Droughts are projected to increase in length and geographical area, leading to increased water shortages, particularly in southern Australia.

Storms and more floods

More frequent and intense storms and rainfall events are predicted with increases in storm and flood damage to ecosystems, housing and infrastructure. Sea level rise is also likely to increase the risk of tidal surges and flooding in coastal regions and communities.

Agriculture and food production

While Australian farming techniques have been developed to cope with Australia’s harsh and variable climate, there are severe limits to the capacity of agriculture to adapt to more extreme changes in temperature and rainfall. Impacts from current climate change projections include:

  • Reduced agricultural production due to rising temperatures, reductions in average rainfall and more frequent and severe extreme weather events.
  • Significant changes to the total area in which crops are likely to be viable.
  • Fewer food surpluses, with the likelihood of deficits in some years. This will have important consequences for Australian farm exports as well as for domestic food security.

Australian cities

Key challenges from climate change for Australian cities include:

  • Destructive impacts on urban populations and on housing, transport and energy infrastructure of more frequent heatwaves and extreme weather events. Recent research has confirmed the risk that Australian cities such as Melbourne and Sydney may well experience daily temperatures of 50°C if global warming exceeds 2°C.
  • Destructive impacts of sea-level rise and storm surge on Australia’s coastal settlements.
  • Significant financial costs likely to be required to pay for the investment needed to strengthen the climate change resilience of Australian cities and towns.
  • Pressures on urban infrastructure arising from domestic and international climate related migration and refugee flows.

Australian security

The Australian defence forces and security organisations have indicated growing concern about the likely security implications of climate change trends including: The potential for climate change to act as a ‘threat multiplier’ through increases in the frequency and intensity of extreme weather events and through the impacts of climate change on regional societies and economies. The displacement, (by drought, food shortages, sea level rise and storms) of up to 250 million people across west Asia, south Asia, south-east Asia and Indonesia by the end of this century. The abandonment of low-lying Pacific islands and of severe economic disruption in China, Bangladesh and Indonesia, creating a class of dislocated national populations.

Australia lies in the region most vulnerable to the impact of a changing climate, including security threats, resulting from both the onset of long term trends and increased extreme weather events.

The security and humanitarian risk is significantly higher than in other regions of the world. Australia’s geographic position means it cannot afford to take climate security lightly.

Rear Admiral (Retired) Neil Morisetti, former UK Government Climate and Security Envoy

Human health risks

Health risks
Source: American Public Health Association

Health risks from climate change and from ongoing reliance on fossil fuels include:

  • Injury, illness and death from extreme weather events including fires, floods and storms.
  • Increasing morbidity and mortality from heatwaves. Groups at particular risk from heatwaves include children, elderly people, people living in cities and people with pre-existing and chronic medical problems.
  • Increasing risks of infectious and vector borne diseases.
  • Adverse mental health impacts including post-traumatic stress disorder following extreme weather events and disasters. Rising levels of anxiety and depression about future climate change risks and consequences.
  • Higher levels of respiratory disease caused by air pollutants and allergens from coal fired power stations and petrol fuelled motor vehicles.
Health co-benefits
Health co-benefits from action to reduce emissions and address climate change risks
Source: British Medical Journal

As illustrated in the above infographic from the British Medical Journal, there is extensive and increasing evidence of the potential co-benefits for health – and for the natural environment if decisive action is taken to reduce emissions and address climate change risks.

Australian nature impacts

Land species and ecosystems

The effects of current climate change trends on many species of Australian flora and fauna is already evident and includes:

Changes in the geographic range, genetics and life cycles of many animals and plants (for example earlier flowering of plants and changes in bird migration patterns).

  • Accelerating losses of populations and species, particularly groundwater-dependent plants and animals.
  • Warm-adapted species increasing at the expense of cool-adapted species
  • An expansion of new ‘problem’ species and pests, for example insects that can impact food production
  • Rapid transformations in the location and composition of many vulnerable Australian ecosystems including, in particular:
    • the alpine zone, which is already experiencing the impacts of reduced snowfalls
    • the wet tropics of north Queensland
    • low-lying freshwater swamps (particularly in Northern Australia) affected by saltwater intrusion
    • inland rivers and wetlands affected by reduced rain and increased evaporation of groundwater
    • groundwater-dependent plants and animals
Source: Australia State of the Environment 2016

Coral reefs and other marine ecosystems

Rising water temperatures and ocean acidification are already causing severe and widespread coral bleaching to the Great Barrier Reef and other Australian coral reef ecosystems. Other climate change trends indicate that current and future impacts on marine ecosystems include:

  • the destruction of kelp forests
  • the southwards shift in distribution of many fish species
  • changes in fish migration and reproduction patterns
  • disruption to fisheries and aquaculture from ocean warming and acidification, from new marine diseases and from the increased incidence of alien fish species in Australian coastal waters

Acting on climate change — from global to local

Paris agreement

The 2015 Paris Agreement sets out a global roadmap for combating climate change. The Paris climate agreement was adopted by almost 200 nations in 2015 and came into effect in November 2016. In 2018 the US pulled out of the Agreement and there have also been calls for Australia to do the same.

The Agreement aims to strengthen the global response to climate change trends by keeping a global temperature rise this century well below 2 degrees Celsius above pre-industrial levels and to pursue efforts to limit the temperature increase even further to 1.5 degrees Celsius. It also increases the ability of individual countries to deal with the impacts of climate change, taking into account their own circumstances and this is to be achieved through “nationally determined contributions” (NDCs).

Under the agreement, all signatories must report regularly on their emissions and on their implementation efforts. There will also be a “global stocktake” every five years to assess the collective progress towards achieving the purpose of the agreement and to inform further individual actions. It is clear however that current policy commitments and actions will need to be rapidly accelerated if the target is to be achieved.

Achieving the goal of keeping global temperatures below 1.5 or 2°C will require greenhouse gas emissions to peak by the early 2020s followed by rapid reduction to as close to zero as possible by 2040. The actions required to achieve swift reductions in emissions are now well understood. Governments need to introduce policy to promote:

  • rapid reductions in energy consumption and improvements in energy efficiency
  • rapid electrification and replacement of fossil fuels by renewable energy
  • low carbon land use and sequestration of carbon into sustainable carbon sinks

Pathways to Deep Decarbonisation in 2050

How Australia can prosper in a low carbon world

Source: Climate Works

Australia ratified the Paris Agreement on 6 November 2016 with the Federal Government setting an NDC target of reducing GHG emissions, (including land use, land use change and forestry (LULUCF),) by 26–28 per cent below 2005 levels by 2030. However, there is a large and ongoing gap between current Australian emissions targets and the pathway required to achieve the Paris Climate Agreement goals. Climate Works Australia recently assessed emissions data and projections against findings from their Pathways to Deep Carbonisation project. With emissions in 2017 at 11 per cent below 2005 levels, Australia is not on track to meet the Paris target. In addition, emissions are projected to rise in most sectors. This is consistent with the Climate Action Tracker (CAT) assessment of the Australia Commonwealth Government’s emission reduction policies last year:

We rate the [Australian] NDC target itself ‘Insufficient’, with a level of ambition that — if followed by all other countries — would lead to global warming of over 2°C and up to 3°C.

Australia: Paris Agreement 26-28 per cent emission reduction target versus carbon exports in coal

(million tonnes CO2-e per annum)

Emissions reduction

If the CAT were to rate Australia’s projected emissions levels in 2017 under current policies, we would rate Australia ‘Highly insufficient’, indicating that Australia’s current policies in 2017 are not consistent with holding warming to below 2°C, let alone limiting it to 1.5°C as required under the Paris Agreement, and are instead consistent with warming between 3°C and 4°C.

This means Australia’s current policies are not in line with any interpretation of a ‘fair’ approach to the former 2°C goal, let alone the Paris Agreement’s 1.5°C limit.

The question of coal

One particularly concerning trend is the impact of Australia’s rapidly growing coal exports on global emissions. Australia exports almost twice the emissions which we produce domestically, with one in every 35 tonnes of global emissions coming from Australian exported coal. This trend will be further accelerated if new coal export projects like the Adani coal mine and others in the Galilee Basin are approved.

Australian domestic and coal export emissions 2016 Source: Renew Economy.

Community support for rapid and decisive climate action

While Australia’s national emissions reduction targets and actions remain well below the level required, many communities, business leaders, investors and state governments are demonstrating growing awareness of the urgent need to address climate risks.

In 2018 the Australia Institute’s ‘Climate of the Nation’ survey found that:

  • 73 per cent of Australians are concerned about climate change trends – up from previous years.
  • 67 per cent want Australia to phase out coal fired power generation over the next two decades.

In Victoria, the 2016 Sustainability Victoria climate change survey also found strong support for decisive action on climate change.

  • The top three impacts that concern Australians are: floods and droughts affecting food production and supply (78 per cent); destruction of the Great Barrier Reef (77 per cent); and more bush fires (76 per cent).
  • 91 per cent accept some level of human causality for climate change.
  • 78 per cent are concerned about the impact of climate change on future generations.
  • 78 per cent think climate change is an issue that requires urgent action now.
  • 79 per cent would be proud to live in a state leading the way on climate change.

Attitudes to responsibility for climate action

Climate of the nation survey results 2017

Attitudes to climate change
Source: The Australia Institute

Government action

There is also growing awareness among local, state and territory governments of the urgent need to take mitigating action to address the physical and economic risks of climate change. The Victorian and Australian Capital Territory Governments have committed to net zero emissions by 2050 and in Victoria the pledge is to reduce greenhouse gas emissions by 15-20 per cent below 2005 levels by 2020. Likewise, the Australian Capital Territory government has pledged 40 per cent reduction in greenhouse gas emissions on 1990 levels by 2020 and 100 per cent renewable energy by 2020. The Sydney City Council is an example of a regional government leading climate change adaptation. The City is Australia’s first carbon neutral government with ambitious targets to reduce emissions by 70 per cent by 2030 on 2006 levels. Sydney and Melbourne City Councils are part of the C40 global network of 96 governments taking local and regional action on climate change.

Business and financial

The chorus of concern from the corporate world is growing in volume.

The forecast for our planet, the environment and our communities is not pretty.

We don’t want to go there. Some cope by denying any of this is happening. But the longer we dither, the harder others will need to work to slow the pace of change. And the more we will need to pay to repair the damage and compensate victims.

The business community accepts this and many organisations are at varying stages of factoring climate policy and physical risks into strategy and risk responses.

Chi Mun Woo, Partner, Sustainability for KPMG

In 2016 the Australian Centre for Policy Development released a legal opinion prepared by the President of the New South Wales Bar Association which concluded that company directors who fail to consider the impact of foreseeable climate change risks on their business could be held personally liable for breaching the duty of due care and diligence they owe to their companies.

While climate risks have been broadly recognised, they have often been seen as a future problem or a non-financial problem.

Many of these risks are foreseeable, material and actionable now.

There could be either sharper, more significant policy changes and market adjustments down the track, or the physical impacts of climate change could become more severe, more likely and more unpredictable.

Geoff Summerhayes, Executive Board member of the Australian Prudential Regulation Authority

The international investor movement to divest from fossil fuels is another example of powerful action taken by capital. Over 852 organisations and 59,524 individuals have pledged to make no new investments in the top 200 oil, gas, and coal companies and to scale back investments over the next three to five years. The combined assets of these divestment supporters is $6 trillion. Australian individuals and philanthropic foundations are participating in this campaign.

In 2015 Bank of England Governor Mark Carney warned investors and business leaders of the urgent need to recognise and address climate risk, highlighting three major areas of concern:

  • physical risk around the effects of climate change
  • transition risk from the shift towards a net zero emissions economy
  • liability risk for company directors, trustees, and insurers

Community and not-for-profit

The perceived policy vacuum on climate change and energy has seen individuals and not- for-profit organisations taking action on climate change. Advocacy to strengthen the commitment of Australia’s governments to climate action and to stop developments which result in high emissions – such as new coal mines and broadscale tree clearing – are core business for a number of large and small organisations. There are also organisations seeking stronger vehicle emission and building standards, and better incentives to accelerate the adoption of emission-reducing technologies such as renewable energy.

Examples include locally organised initiatives, community owned generators and programs to increase awareness of energy saving measures. There are also a wide range of activities which aim to protect and enhance the carbon stored in native vegetation, which has both climate and biodiversity benefits. This includes indigenous land management programs, where traditional vegetation burning regimes are encouraged to prevent wildfires. Given the significant risk climate change presents to agriculture, a growing number of farmers are participating in advocacy and also adopting innovative land and water management techniques (for example: Farmers for Climate Action).

An increasing number of charities are looking for ways to further their social missions while dealing with the implications of climate change trends. The Brotherhood of St Laurence has a research agenda focusing on ways to reduce climate change impacts for people on low incomes. There is also a new, growing Just Transitions movement, supporting communities to transition their economies away from fossil fuel extraction or generation. The movement looks to sustainable economic solutions as a means of saving these communities from decline, but also to address current disadvantage or inequality.