“Climate change is the greatest health challenge of the 21st century”. Such is the conclusion of the latest report by the World Health Organization (WHO), released last month to coincide with the COP24 climate conference in Katowice, Poland. The report makes clear that immediate action on climate change is necessary to mitigate the extensive health impacts of climate change and that meeting the goals of the Paris Agreement would save one million lives from reductions in air pollution alone.
The direct impacts of increasing global temperatures include death, injury, and illness as a result of temperature extremes.
Each year, air pollution kills an estimated 7 million people. The burning of fossil fuels results in emissions that are the main drivers of climate change. Carbon emissions are a major contributor to air pollution, which is responsible for more than a quarter of all deaths from heart disease, 43% of deaths from chronic obstructive pulmonary disease, and nearly a third of deaths from lung cancer.
In addition to lives saved, the economic value of the health gains from reducing air pollution are approximately twice the cost of the policies required.
A 2018 study found that the health benefits of emissions reductions to achieve the 2ºC target would offset the economic costs of treating illness from air pollution in China and India completely. In the European Union and in the United States, while varied, reductions in such costs could be substantial (covering between 7-84% and 10-41% respectively). In India and China, pursuing a reduction in emissions to achieve a 1.5ºC target would result in significant net benefits: US $3.28-8.4 trillion in India and $0.27-2.31 trillion in China.
Beyond air pollution, the health impacts of climate change are extensive and multipronged.
The direct impacts of increasing global temperatures include death, injury, and illness as a result of temperature extremes, including longer and more intense heat waves and fires.
The extreme weather events arising as a result of climate change include floods, the most common natural disaster, and storms which result in drowning, injuries, and, when combined with the effect of the warming oceans, can contribute to outbreaks of infectious disease. Rainfall patterns and temperatures are critical in influencing how pathogens grow and spread in the environment and in hosts, as well as how vectors, such as mosquitoes, breed and bite. Shifting rainfall patterns are likely to affect the spread of the Aedes aegypti mosquito: the vector for diseases including dengue fever, zika, yellow fever, and chikungunya.
Climate change also impacts human systems, including agriculture and the quality, nutrition, and availability of food. In addition to reducing emissions so as to limit global warming and mitigate the impact of climate change, countries will have to implement adaptation measures that reduce the intensity of these effects, especially for the most vulnerable populations who will disproportionately carry the burden of climate change.
At the COP24 climate talks, WHO Director-General Tedros described the Paris Agreement as “potentially the strongest health agreement of this century”.
Adopted three years ago, parties to the Paris Agreement agree to seek to keep global increases in temperature to below 2ºC and to pursue efforts to limit the increase in global temperatures to 1.5ºC.
To limit global warming below these levels requires significant, immediate global reductions in greenhouse gas emissions. However, instead of setting specific, legally-binding emissions targets, parties to the Paris Agreement self-determine what steps they will take to meet the agreement’s goals (known as Nationally Determined Contributions or NDCs) and commit to undertake rapid reductions to achieve a net-zero greenhouse gas emissions by the second half of the 21st Century.
Last year, the United Nations Environmental Program released its Emissions Gap Report, assessing parties’ progress in meeting their NDCs. The report found that while it is technically still possible to ensure global warming stays well below 2ºC and 1.5ºC, current NDCs are inadequate: if current NDCs and emissions proceed, the world is on track for warming of about 3ºC by the end of this century.
If NDCs are not significantly revised to reverse this trend by 2030, global temperature increases exceeding an increase of 1.5ºC will be unavoidable. If emissions reductions are not reduced sufficiently quickly, the Earth could be pushed past its stabilisation point onto a “Hothouse Earth” pathway where we experience continued global warming even after anthropogenic emissions are reduced.
Australia’s inaction in reducing emissions to mitigate climate change and air pollution is unacceptable, unethical, and damaging to Australia’s health. The Climate Action Tracker rates Australia’s NDCs as insufficient, “in the least stringent part of their fair share range”, and not consistent with limiting warming below 2ºC, let alone 1.5ºC.
The Australian Bureau of Meteorology and the CSIRO recently released its State of the Climate Report 2019, warning that Australia is set to experience more frequent and intense heatwaves and extreme fire weather as a result of climate change. While the international negotiations in Poland are critical, the urgent action required to mitigate the impacts of climate change must begin at home.