HOW HOT CAN IT GET?

Having crossed the 1.5°C global warming threshold on several occasions in 2024, the world is now headed into an era of increasingly dangerous and unpredictable weather. A decade ago, 1.5°C was identified as a tipping point to avoid climate disasters. But now we are here – and the temperature will continue to rise if humanity doesn’t do a lot more to curb greenhouse gases over the next few years. If we keep releasing carbon dioxide into the atmosphere at our current rate, there’ll be severe consequences for animals, plants, humans, and the planet itself.

The 1.5°C target, set in the Paris Agreement, was seen as critical to minimize the worst consequences of global warming. Unfortunately, this past year, global temperatures have approached this threshold and even gone over it on some days. This plays into extreme weather events like El Niño, and definitely made 2024’s hurricanes more damaging than they otherwise would have been.

Most scientists agree: barring huge reductions in greenhouse gas emissions, the world will permanently exceed 1.5°C in the next decade. Crossing this threshold marks the beginning of more frequent and intense heatwaves, rising sea levels, and increasingly erratic weather.

The extent of future warming between now and 2070 depends on how effective efforts to curb emissions are. The Intergovernmental Panel on Climate Change lays out several scenarios:

1. For the Optimists
If the world takes immediate and aggressive action to reduce carbon emissions, global warming could be limited to around 1.5-2°C by 2070. This would require a near-total shift away from fossil fuels by 2050, the widespread adoption of renewable energy, reforestation, and improvements in energy efficiency. In this best-case scenario, while more intense heatwaves, hurricanes and tornados exist, the worst case outcomes can be avoided.

2. For the Moderates
If emissions reductions are moderate, the world is likely to become 2.5-3°C hotter by 2070. In that case, the impacts would be way more severe. Extreme heatwaves would become the norm in many parts of the world, with temperatures regularly exceeding 45°C or 50°C in tropical regions; that’s roughly 118°F. At that temperature, expect to see spikes in heat-related mortality, food shortages due to crop failures, and economic instability in tropical areas. Arctic ice would also melt much more quickly, making the seas rise; many ecosystems would collapse.

As we near 2°C, the livability of large areas of the Earth comes into question. When the “wet-bulb temperature” – a combination of heat and humidity on Earth – exceeds 35°C, the human body can no longer cool itself through sweating, making survival without air conditioning impossible. By 2070, significant parts of the world may approach or exceed this threshold, displacing millions and triggering large-scale migration.

3. For Pessimists & Realists
If emissions continue at the current pace or increase, global warming could exceed 3.5-4°C by 2070. In this scenario, large parts of the world would be uninhabitable. Cities in the Middle East, South Asia, and parts of Africa could experience regular temperatures exceeding 50°C or 122°F, with some regions reaching levels incompatible with human life. Heatwaves that now occur once every few decades would probably happen every year, while droughts, wildfires, and storms would become far more frequent and devastating.

It’s important to note that some regions will experience much higher temperature increases than others. The Arctic is warming two to three times faster than the global average – and tropical regions will likely bear the brunt of the heat, pushing densely populated parts of India, Southeast Asia, and Africa that’re already struggling with heatwaves over the edge.

The choices we make in the next few decades will determine the future of life on Earth and whether it’s possible to adapt to an increasingly hostile climate.