In Short : I previously believed the climate crisis would lead to widespread fatalities. I now acknowledge the complexity of the issue and recognize the need for collective efforts to address and mitigate its impact, fostering hope for a more sustainable future.
In Detail : In an extract from her book Not the End of the World, data scientist Hannah Ritchie explains how her work taught her that there are more reasons for hope than despair about climate change – and why a truly sustainable world is in reach
“Scientists say temperatures could rise by 6C by 2100 and call for action ahead of UN meeting in Paris” – Independent, 2015.
A world that was 6C warmer than it is today would be devastating. And remember, 6C is just the average. Some parts of the world would get much warmer, especially the poles. Crops would fail. Many people would be malnourished. Forests would be stripped back into savannahs. Island nations would be completely submerged. Many cities will have disappeared due to sea-level rise. Climate refugees will be on the move. “Normal” temperatures in many parts of the world would be unbearable. Even the richest, most temperate nations would see devastating floods most winters and baking summers. We would be at very high risk of setting off warming feedback loops – the melted ice would reflect less sunlight, the melted permafrost might unlock methane from the bottom of the ocean, and dying forests wouldn’t be able to regrow to suck carbon out of the atmosphere. A 6C warmer world might be short-lived – it could quickly spiral into 8C, 10C or more. It would be a massive humanitarian disaster.
Only a few years ago, I thought this was where we were headed. Forget 1.5C or 2C – we were destined for 4C, 5C or 6C and there was nothing we could do about it. Most people still think that this is the path we’re following. Thankfully, it’s not.
In 2015, I went to Paris for the big, famous climate conference, Cop21. Representatives and policymakers from every country came together to hash out a new climate deal. The previous goal of the international agreement was to keep the global average temperature rise below 2C by the end of the century. So I couldn’t believe it when there were rumours that a target of 1.5C was being discussed. Were they crazy? At that point, I had already given up on the prospects of 2C. It was so far out of our reach. The notion that we could keep the rise below 1.5C seemed delusional. And yet the target made it into the final agreement. Mostly as an aspiration, but it was in there nonetheless. The world pledged to “limit global warming to ‘well below’ 2C above pre-industrial levels and also, if possible, ‘pursue’ efforts to cap warming at 1.5C”.
My perspective on 1.5C hasn’t shifted much since then. Without a major, unexpected technological breakthrough, we will go past this target. Nearly all the climate scientists I know agree: they obviously want to cap warming at 1.5C, but very few think it will happen. This doesn’t stop them fighting for it, though; they know that every 0.1C matters, and is worth working for. But my perspective on 2C has changed. I’m now cautiously optimistic that we can get close to it. It’s more likely than not that we will pass 2C, but perhaps not by much. And there is still a reasonable chance – if we really step up to the challenge – that we can stay below it.
My perspective flipped quickly after studying the data, not newspaper headlines. I didn’t focus on where we are today, but on the pace that things have moved at in the past few years, and what this means for the future. One organisation – the Climate Action Tracker – follows every country’s climate policies, and its pledges and targets. It combines them all to map out what will happen to the global climate. At Our World in Data, I sketch out these future climate trajectories and update them every year. Every time, they get closer and closer to the pathways we would need to follow to stay below 2C.
If we stick with the climate policies that countries currently have in place, we’re heading towards a world of 2.5C to 2.9C warming. Let me be clear: this is terrible and we have to avoid it. But countries have pledged to go much further. They’ve committed to making their policies much more ambitious. If each country was to follow through on their climate pledges, we’d come out at 2.1C by 2100.
What’s most promising is how these pathways have shifted over time. In a world without climate policies, we’d be heading towards 4C or 5C, at least. This is the path that most people still think we’re on. That would be a scary world indeed. Thankfully, over time, countries have stepped up their commitments. As we saw with the example of the ozone layer, incremental increases in ambition can make a huge difference.
The other big change is that moving to a low-carbon, sustainable economy is not seen as the sacrifice it used to be. Fossil fuels were far cheaper than renewables. Electric vehicles cost a fortune. But now low-carbon technologies are becoming cost-competitive. It now makes financial sense to take the climate-friendly path. Leaders have become more optimistic about how the landscape is changing. We are still some distance from a 2C pathway. We need to step up our efforts – and quickly. But as it becomes more and more realistic, I’m confident we can keep moving closer to it.