Climate change, 1.5C or 2C: Which one is better in the era of coronavirus?

By Asitha Jayawardena

Today, global average temperature has increased to about 1oC from the pre-industrial period. It is now on the rise by 0.2oC every decade. In other words, it will reach 1.5oC somewhere around 2040.

In December 2019 coronavirus hit China and thereafter it spread into other countries. At the time of going to the press, it stands in countries in all continents with China, Italy, Iran, Spain, United States and South Korea in the lead. The total number of dead stands over 36,000.

What happens when coronavirus and climate change are considered together.

In Wuhan, China, the disease broke out and eventually it lowered the electricity demand. This should be considered as the country which is the largest carbon dioxide emitter in the world. For example, coal consumption at power plants was down 36% and lowering of the oil refinery capacity by 34%.

Moreover, NASA satellite images show that the pollution levels went down with reduced activity with the industries in China and other countries.

In the meantime, the other countries are affected similarly, not like China but to a significant level. For instance, less people would travel in otherwise crowded trains and restrictions are in place to visitors of various countries.

Suppose we have a type of virus in the full swing, say coronavirus. Then what is the global annual temperature that we need to focus on, as agreed in The Paris Agreement in 2015? 1.5 or 2oC?

Now we must go back to the Special Report, Global Warming of 1.5oC, published by the Intergovernmental Panel on Climate Change in October 2018. Let’s consider several points.

Extreme heat: By sticking to 1.5oC, global population that would be exposed to extreme heat at least five years would be 14%. If 2oC, the value would be 37%, with an increase of 2.6 in terms of impact.

Ecosystems: With 1.5oC warming, the amount of Earth’s land which shift to a new biome is only 7%. When warming is 2oC, the corresponding figure nearly doubles, to 13%.

Sea ice-free Arctic: The number of sea ice-free summers would be at least once in every 100 years if we stick to 1.5oC. The number is reduced to 10 years if we resort to 2oC, worsening 10 times.

Permafrost: Warming of 1.5oC will thaw 4.8 million km2 of permafrost in Arctic. With 2oC, it would be 6.6 million km2, an increase of 38%.

Sea level rise: If we aim to maintain 1.5oC, the amount of sea level rise in 2100 would be 0.4 meters. Relaxing to 2oC would enhance to 0.46 meters, as increase of 6cm.

Other parameters will further make 1.5oC warming more suitable than 2oC.

Coronavirus or not, we must stick to that: 1.5oC better than 2oC. That is the lesson we must learn.

References

worldometer https://www.worldometers.info/coronavirus/coronavirus-death-toll/

Coronavirus: Lockdowns continue to suppress European pollution https://www.bbc.co.uk/news/science-environment-52065140

Half a Degree and a World Apart: The Difference in Climate Impacts Between 1.5˚C and 2˚C of Warming https://www.wri.org/blog/2018/10/half-degree-and-world-apart-difference-climate-impacts-between-15-c-and-2-c-warming

A Degree of Concern: Why Global Temperatures Matter https://climate.nasa.gov/news/2878/a-degree-of-concern-why-global-temperatures-matter/