Why even 1°C of global warming matters

The planet has already warmed 1°C from the pre-industrial period. But the question many people still ask is why does it matter? Isn’t 1 degree just small a number to be worried about?

“The scales of the planet is different from the temperature scales we experience on a daily basis,” said Gavin Schmidt, director for NASA Goddard Institute for Space Studies, at the Congress International de Cambio Climatico (International Congress on Climate Change) held in Huelva, Spain last May 10-12.

“One degree of warming matters. It is similar to one quarter of the ice age of 20,000 years ago to pre-industrial change,” Schmidt added.

The difference of global temperature between the pre-industrial period and the last ice age is about 4-5 degrees celsius. However, 20,000 years ago, in the last quarter of the ice age, ice thawed because of an increase in carbon dioxide in the atmosphere which warmed the planet. This is according to a paper published in Nature. This warming caused the last deglaciation and within a few hundred years, seas have risen to as much as 10 meters in some areas, and frozen land in Asia, Europe, and North America ceased to be so.

But this all happened even before man-made climate change, before man learned how to burn coal, oil, and gas to fuel its energy needs. Today, the planet is warming at an alarming rate, where the “hottest year on record” has now become whatever year it is.

The Paris Agreement, which has now been ratified by 145 countries that are part of the United Nations Framework Convention on Climate Change (UNFCCC), included the long term goal of holding global warming to 1.5 degrees above pre-industrial period. However, according to an analysis by Carbon Brief, there are only four years left before we burn our carbon budget.

What is the carbon budget? It is the amount of carbon dioxide we can emit and still keep global warming to 1.5, 2, or 3 degrees celsius above pre-industrial level. At the rate we are going, we will be using up all our carbon budget in 4 years.

“The rate at which we are decarbonising is not sufficient to keep us at 1.5 or 2 degrees. We are going to shoot through 1.5, that’s for sure,” Schmidt agrees.

Climate Analytics, on the other hand, have made a feasibility study on limiting warming to 1.5 and 2 degrees, citing the need for a lot of negative emissions such as Carbon Capture and Storage to be able to do so.

The difference between 1 degree of warming is stark. Typhoon Haiyan (local name Yolanda) happened at 0.8 degrees of global warming. Can we imagine what happens at 1.5 or 2 degrees of warming? Countries like the Philippines are most at risk — islands will sink, typhoons stronger than Haiyan will come, drought will become longer, food and water security will be threatened.

November 11, 2013: An aerial view of a coastal town in Samar province, devastated by super Typhoon Haiyan. (Reuters)

Schmidt, however, remains hopeful for the future.

“These targets are long term targets, not targets to be met at a particular time. We are going to go past 1.5 degrees, but we can go back down with aggressive mitigation measures,” he said.

“The future is not certain. Depending on how we choose to deal with this problem — whether we have aggressive mitigation measures or we burn everything and go on business as usual — the difference between the two, that’s what we can control. It’s not too late. The next chapters in the  climate story had not yet been written, and it’s the choices we make now, individually, in our cities, in our states, in our countries, in the European Union, internationally — it’s those choices that will determine how the story goes.” he added.


Originally published at GMA News