- Under the 2015 Paris climate accord, nearly 200 countries committed to reducing the carbon emissions that fuel climate change and keeping global warming under 2˚C (3.6°F), or 1.5 ˚C (2.7°F) if possible.
- The 1.5°C goal requires global greenhouse emissions to be cut by 45% by 2030 and brought down to net zero by 2050, which is extremely unlikely to happen, a new analysis has found.
- Even if mean temperatures were held below 2°C, people living in the tropics, in particular in India and sub-Saharan Africa, will be exposed to extreme heat for most days of the year, researchers warned.
- In the mid-latitude zone, which includes the U.S. and most of the European Union and the U.K., deadly heat waves could strike every year by 2100.
Climate scientists say there’s a 0.1% chance of keeping warming below 1.5° Celsius (2.7° Fahrenheit) by 2100, as called for in the Paris Agreement.
Even the less ambitious target of limiting the temperature rise to 2˚C (3.6°F) above pre-industrial levels is unlikely too, researchers from the University of Washington, Seattle, projected. Global mean temperatures could breach the 2˚C mark as soon as 2050, their new study in Communications Earth & Environment predicts.
In 2021, Earth had already warmed by more than 1˚C above pre-industrial levels, according to the World Meteorological Organization (WMO). Despite these dire warnings, we continue to pump carbon dioxide and other greenhouse gases into the atmosphere.
Nearly 200 countries signed the Paris climate accord in 2015, committing to curtail the carbon emissions that fuel climate change. They settled on 2˚C as a safe target to avoid the most dangerous impacts of interfering with the planet’s climatic system, while calling on governments to aim for 1.5˚C.
However, a 2019 report from the Intergovernmental Panel on Climate Change (IPCC) documented just how much more detrimental going from 1.5˚C to 2˚C would be, especially considering sea level rise, impacts on biodiversity, and extreme weather events. In recent years, climate activists and civil society groups have intensified calls to hold the average temperature rise to less than 1.5˚C.
“The 1.5°C figure is not some random statistic,” WMO Secretary-General Petteri Taalas said earlier this year in a prepared statement. It is “rather an indicator of the point at which climate impacts will become increasingly harmful for people and indeed the entire planet.”
This month, U.S. President Joe Biden signed off on an expansive bill that includes provisions to slash U.S. greenhouse gas emissions by 40% from 2005 levels by 2030. The U.S. is historically the largest carbon polluter, but since 2006 China has overtaken it in terms of total annual emissions. Last year, China said its emissions will start to decline before 2030. The country is on track to get there by 2025. It’s also aiming for net-zero carbon emissions by 2060.
However, the 1.5°C goal requires that global greenhouse emissions be cut by 45% by 2030 and brought down to net zero by 2050.
In their new research, the U.S.-based scientists warned that even if mean temperatures are locked below 2°C, people living in the tropics, in particular in India and sub-Saharan Africa, will be exposed to extreme heat for most days of the year.
Rising temperatures bear on human health in different ways — from causing short-term effects like cramps and heat exhaustion, to aggravating chronic illnesses, especially among elderly people. Workers employed outdoors and economically poorer groups, with limited access to relief, are also at high risk.
A study earlier this year said that between 2011 and 2020 there were between 12,000 and 19,000 heat-linked child deaths in Africa. They suggested that climate change played a role in about half of the fatalities. Progress in health care and food security that could cut child mortality is being undermined by the impacts of climate change.
It’s not just the tropics that will experience deadly heat stress. The heat waves that swept across Europe this summer, with record-breaking temperatures in England, Scotland and France, could become the new normal.
In mid-latitude areas, including in the U.S. and most of the European Union and the U.K., heatwaves that would hit once in a few years could occur every year by 2100. The study authors forecast a 16-fold rise in the chance of heat waves in the city of Chicago.
At the last high-level climate talks, in Glasgow, Scotland, parties to the Paris accord agreed to slash global carbon dioxide emissions nearly in half by 2030 in line with the 1.5°C goal. The next climate summit, COP27 in Egypt in November, will see the parties take stock of the progress made on these promises.
Banner image: Even if mean temperatures were held below 2°C, people living in the tropics, in particular in India and sub-Saharan Africa, will be exposed to extreme heat for most days of the year, researchers warned. Image by Gyan Shahane via Unsplash (Public domain).
Citations:
Vargas Zeppetello, L. R., Raftery, A. E., & Battisti, D. S. (2022). Probabilistic projections of increased heat stress driven by climate change. Communications Earth & Environment, 3(1). doi:10.1038/s43247-022-00524-4
Chapman, S., Birch, C. E., Marsham, J. H., Part, C., Hajat, S., Chersich, M. F., … Kovats, S. (2022). Past and projected climate change impacts on heat-related child mortality in Africa. Environmental Research Letters, 17(7), 074028. doi:10.1088/1748-9326/ac7ac5