1.5˚C is the new 2˚C

By Christopher Weber, global climate & energy lead scientist, WWF

© Michel Gunther / WWF

Scientists and governments from around the world have been meeting in Korea this week to discuss a landmark report that outlines what it will take to keep global warming to 1.5℃. The Intergovernmental Panel on Climate Change (IPCC) Special Report on Global Warming of 1.5°C makes clear that allowing temperatures to rise beyond 1.5°C will have devastating consequences, including loss of natural habitats and species, even higher sea-level rise, dwindling ice-caps, spreading deserts and catastrophic storms.

1.5°C is safer than 2°C for people and nature

Scientists are now increasingly aware that every half a degree matters to people and nature, and new science is making clear that many of the impacts we thought we’d see at 2°C we will now likely see sooner, some at 1.5℃ or lower. And above 2°C we may face irreversible impacts and unstoppable change. So in many ways 1.5°C is the new 2°C.

Our current emissions, unless curbed, will breach crucial tipping points sooner than expected causing irreversible impacts — including the loss of nature which will be disastrous for people and our environment and economies, pushing us to limits where adaptation is impossible, with many communities already suffering the consequences of loss and damage.

Climate change is happening now

It’s not only scientists warning us that temperatures rising 2°C or more is dangerous, it’s also nature. This is evident from extreme weather events like the heatwaves in Japan and Europe, wildfires in California and Greece and devastating superstorms in the Philippines, a stark reminder of what climate-related impacts look like in a world that is already 1°C warmer than pre-industrial levels. The UN estimates that, in the last 10 years, climate-related disasters have caused $1.4 trillion of damage worldwide.

We can’t delay taking climate action

There’s no question that limiting global warming to 1.5°C will be hard. We are nowhere near the scale of action required based on current commitments from national governments under the Paris Agreement, nor commitments from businesses and local leaders as a whole.

Delivering on this temperature goal by cutting emissions will require very rapid change in our energy and land systems, as well as behavioural changes such as dietary shifts, that will only get harder the longer we wait. In fact, recent science shows that hitting the 1.5°C target will be nearly impossible without large scale carbon dioxide removal, which could involve risky and unproven technologies, if we do not act quickly to raise ambition. Acting immediately will allow us to benefit from nature-based solutions that we know how to deploy, like sustainable agriculture and forest restoration.

Although we face difficult choices, there are signs of optimism as well. First and foremost, the underlying science has shown that achieving the 1.5°C target is feasible, if we significantly increase the ambition of emission reduction targets now. As one particularly bright spot, renewable energy options and energy storage are already the cheapest investment option in many places and are poised to outcompete fossil fuel-based energy globally within 5–10 years.

Solutions already exist

The report underscores the critical need for urgent and transformative climate action, and it provides detailed signposts for governments on what is required and when in order to deliver on 1.5°C. We know from science that in order to reach 1.5°C, we need to fully decarbonize the economy — or be at “net zero” CO2 emissions — by 2050, preferably 2040. This will mean significantly scaling out finance for developing countries to cut emissions and help communities adapt.

This broad signpost is critical, but we also need near term targets, notably from now until 2030. Our existing policies are inadequate — currently estimated to deliver a 3°C world — while economically viable opportunities for strengthening 2030 goals are staring us in the face, including deploying cost-effective renewable energy, halting deforestation, and investing in low-carbon transportation and buildings.


While we act with urgency to cut emissions we must also increase our ambition with respect to adaptation. Climate adaptation to climate change is already needed at the current global warming of 1°C, and will increasingly be needed as temperatures rise. However, there are limits to adaptation, particularly for low-lying and coastal countries, and highly sensitive ecosystems such as coral reefs and polar regions. These limits to adaptation and associated losses exist at every level of global warming and increase with temperature rise, which is why we must act quickly.

Leaders must show climate leadership

Now is the moment for governments, businesses, and the world as a whole to step up their climate ambition to avoid crossing a dangerous line of 1.5°C. We have the tools, we have the targets, and we now know that the only difference between impossible and possible is political leadership.

Christopher Weber is global climate & energy lead scientist at WWF.


Originally published in Reuters on 8 October 2018