The UN’s Intergovernmental Panel on Climate Change (IPCC) released its Special Report on Global Warming of 1.5°C on Monday. It clearly states that the impacts of climate change will be greater at a lower degree of warming than previously thought.
Written by 91 scientists from 40 countries, the report finds that quick and dramatic action needs to be taken to avoid a warming increase of 1.5°C (2.7°F) above pre-industrial levels. Without aggressive cuts to global greenhouse gas emissions, the planet is expected to reach this warming threshold between 2030 and 2052.
The Paris Agreement set the target of holding global warming to 2°C (3.6°F) above pre-industrial levels and urged countries to pursue an even tighter cap of 1.5°C (2.7°F) if possible. This more aggressive goal was added at the urging of officials from low-lying island nations – those most susceptible to sea level rise. As such, the IPCC began to look more closely at what 1.5°C (2.7°F) of warming would mean for people and ecosystems around the planet.
Previously, scientists thought that the most severe effects of climate change could be held off if the planet stayed below 2°C (3.6°F) of warming. However, this report shows that those impacts will come sooner, at the 1.5°C (2.7°F) mark. These consequences include coastal inundation from rising seas, worsening droughts and wildfires, as well as food shortages and mass die-offs of coral reefs. An extra half-degree Celsius, from 1.5°C to 2°C, would magnify those impacts.
To avoid the worst case of these types of effects, the report says the global economy needs to be transformed within the next few years. More specifically, greenhouse gas pollution must be reduced by 45% from 2010 levels by 2030, and 100% by 2050. While this is technically possible, the report also highlights it will require enormous political will.
Under the Paris Agreement, every country around the globe submitted individualized plans to reduce its greenhouse gas emissions known as nationally determined contributions (NDCs). While an important first step, these are not enough to meet the agreement’s 2°C (3.6°F) goal, to say nothing of the more aspirational target of 1.5°C (2.7°F). In fact, they would allow for 3°C (5.4°F) of warming by the end of the century. However, the agreement does legally obligate countries to reconvene every five years to present updated plans spelling out how they will deepen their emissions cuts.
For the US, the second largest carbon polluter in the world after China, political will for climate action is something that is sorely lacking. President Trump announced plans to withdraw the US from the Paris Climate Agreement and has been rolling back his predecessor’s Clean Power Plan, the principle aspect of this country’s NDC.
Nonetheless, 2018 marks the halfway point between the passage of the Paris Climate Agreement in 2015 and the 2020 target for countries to begin ratcheting up their greenhouse gas cutting commitments. As such, this new report will be key to the discussions at the upcoming UN Climate Conference in Katowice, Poland this December.