In conversation with Professor Benjamin Horton, Director of the Earth Observatory of Singapore 

1. How might a breach of the 1.5°C Paris Agreement in the next five years impact Southeast (SE) Asia?

This week a new report released by the World Meteorological Organization (WMO) shows there is a 1 in 5 chance annual global temperatures will be at least 1.5°C warmer than in pre-industrial times in the next 5 years. This is very worrying to the planet. From the Paris Agreement, we needed to keep our temperatures below a 2°C temperature rise before the end of this century. The importance of the Paris Agreement cannot be understated.

If we go beyond the Paris Agreement we will cause a destabilisation of the Greenland and Antarctica ice sheets, it will include increase in extreme events such as flooding, droughts, heatwaves and wildfires, degradation of virtually every coral reef on our planet, and massive biodiversity loss.

Here in SE Asia, huge tropical downpours and hot temperatures can impact greatly on human life, ocean health, and critical ecosystems required to keep our planet healthy. 

We are going to see more extremes in the region – the heatwave of 2016 will be repeated more and more in countries across SE Asia over the coming decades. We need to better understand these climate extremes, how we can mitigate and prepare for such changes in our region.

2. Why are scientists extremely worried about the sharp rise of CO² and how is this connected to predicted warming trends and sea-level rise?

This week, from this report, we have been able to decipher accurately the amount of carbon dioxide in a period of the Earth’s history called the Pliocene, which is some 3 million years ago.  This period of time is of tremendous interest to scientists as we think it is an analogy of how the Earth responded to a warming planet driven by a high rise of carbon dioxide.

We know that the Pliocene period had carbon dioxide levels around 430 parts per million by volume. Our carbon dioxide levels prior to the industrial revolution were 280 parts per million, and now we are over 410 parts per million and are fast approaching the Pliocene levels. 

3. Why should we be worried about approaching the Pliocene levels of carbon dioxide in the Earth’s atmosphere?

In the Pliocene temperatures were 3-4 degrees warmer than today, and what were the impacts? The increase in temperature rise caused a staggering 20-metre rise in sea level. But where did this huge volume of water come from? The only option is the large polar ice sheets.

In the Pliocene period around 3.3 million years ago, the Greenland ice sheet melted and disappeared. Vast volumes of fresh water were dispersed into the oceans. In this period the West Antarctica ice sheet also disappeared, pushing high levels of fresh water further into the global oceans. And, in the Pliocene, the stable East Antarctica ice sheet also partially collapsed. All of these combined to cause a massive 20-metre rise in sea level around the planet.  

Obviously, if we have such a high concentration of carbon dioxide in our atmosphere in the future, we will eventually see a similar response in temperature and sea-level rise. What we don’t know is how long it will take for the ice sheets to disappear. Here at the Earth Observatory of Singapore, we are trying to find the answers.

The fate of the ice sheets is one of the most important questions for science. A 20-metre sea-level rise will destroy society as we know it now. Low-lying nations, Oceania nations, many regions across SE Asia will be severely impacted and lost. The world as we know it will be dramatically changed. 

Currently, our CO² levels are rising at about 2.5 ppm per year – meaning that by 2025, we will have exceeded anything seen in the last 3.3 million years on earth.

4. Why is it so important to study the Earth’s past records to better understand our future challenges?

By studying the Earth’s past response to the build-up of greenhouse gases, we can apply this knowledge to help us predict future responses: sea-level impact; temperature; impact on agriculture, health, food security, biodiversity, oceans – the key elements of life on this blue planet.

The information we have received this week showing the critical impacts of a possible future temperature rise of 1.5°C in the next 5 years, and the carbon dioxide values we are approaching, closely parallel a time period in the past where we experienced massive sea-level rises. 

So it is very important for us here at the Earth Observatory of Singapore, here in SE Asia, to study the regional and local effects of climate change and these effects on ecological systems and society.

There has never been a more important time to be an Earth scientist. Our work here at the Earth Observatory of Singapore has never been so critical to ensure we form a clear picture of the challenges that lie ahead, and the best solutions to mitigate these challenges to ensure all people in our region can live a happy and healthy life.

Any delay will diminish the window within which there will still be time to reverse these trends and to bring the temperature back down into those limits.

We need to better understand our changing earth systems, what it means for this region –  particularly in understanding sea-level rise and its potential effects on low lying regions,  food security, and health and regional economic stability here in SE Asia.

We only have until 2030 to drastically reduce our dependence on fossil fuels and prevent the planet from reaching the crucial threshold of 1.5°C above pre-industrial levels.