A new report by the Intergovernmental Panel on Climate Change (IPCC) warns of food shortages, widespread wildfire and dying coral reefs by 2040 if drastic changes are not made.

The report is the result of three years of research from 91 scientists, drawing on more than 600 resources. It also involved extensive consultation with government officials at a recent IPCC meeting in South Korea.

It says the world has not met targets to keep the rise in global temperatures to 1.5°C and is now heading for a potentially calamitous 3°C rise.

Slowing the rise to 1.5°C above pre-industrial levels would involve “rapid, far-reaching and unprecedented changes in all aspects of society”, the report warns with socioeconomically disadvantaged areas likely to be disproportionately impacted.

Coral reefs will be devastated if climate change is not halted, the report warns. Australia’s Great Barrier Reef would be vulnerable and the rising temperature would also deplete fish stocks and diversity.

A temperature rise of half a degree would have a profound impact on flooding, droughts and food supply

“Limiting warming to 1.5°C brings a lot of benefits compared with limiting it to two degrees. It really reduces the impacts of climate change in very important ways,” said Prof Jim Skea, who co-chairs the IPCC.

“The second is the unprecedented nature of the changes that are required if we are to limit warming to 1.5°C- changes to energy systems, changes to the way we manage land, changes to the way we move around with transportation.”

Co-Chair of IPCC Working Group 1, Panmao Zhai, said the report highlights how the world is “already seeing the consequences of 1°C of global warming through more extreme weather, rising sea levels and diminishing Arctic sea ice.”

Hans-Otto Pörtner, Co-Chair of IPCC Working Group II said “Every extra bit of warming matters, especially since warming of 1.5ºC or higher increases the risk associated with long-lasting or irreversible changes, such as the loss of some ecosystems.”

Scientists call on politicians to take action

The scientists concluded that if greenhouse gas emissions are not reduced, the atmosphere will warm up by as much as 1.5°C above pre-industrial levels by 2040, leading to more severe and lengthy droughts, food shortages, poverty and the loss of coastal areas. The estimated cost of these changes would total US$54 trillion.

Coal use also needs to be radically curbed and completely eliminated by 2050, the report says. While new technologies such as electric cars show promise for reducing environmental impact, industries such as shipping, freight and aviation continue to produce dangerously high levels of emissions. The report also urges politicians to ensure a 1 billion ton reduction in emissions for every one of the next 10 years.

A common theme in the report is the lack of political will to make necessary changes to halt climate change. The report calls for higher taxes on carbon dioxide emissions to shift behaviour, nominating a price of US$27,000 per ton by 2100 but there has been significant political opposition to such taxes, particularly from the US, the world’s second-largest greenhouse gas emitter after China.

The political tides have changed significantly since the report was commissioned at the 2016 Paris climate summit. US President Donald Trump announced the US would withdraw from the accord, a process that will be completed by 2019. Similarly, Jair Bolsonaro, the likely next President of Brazil, has also promised to walk away from the accord and welcome agribusiness into the Amazon rainforest.

Header image credit: Diksaeva (@dikaseva)