Carbon-neutral vs. net-zero: what’s the difference?

As part of the Paris Agreement on climate change, countries across the world committed to keep global warming well below 2°C above pre-industrial levels, whilst trying to limit warming to 1.5°C. Restricting warming to 1.5°C is a much more ambitious goal, that involves reducing global emissions to at least 25 Gt CO2e by 2030 and achieving net-zero emissions by 2050. Based on today’s commitments, emissions are on track to reach 56 Gt CO2e by 2030, over twice what they should be. We need to reduce emissions by 7.6% every year until 2030 in order to achieve 1.5°C of warming.

While there will still be impacts of warming at 1.5°C, this is the level scientists say is associated with less devastating impacts than higher levels of warming, whilst still feasibly being achievable. Every fraction of additional warming beyond 1.5°C will result in increasingly severe and expensive impacts. For example if you look at predictions for effects at 1.5°C compared to 2°C of warming:

• The amount of the population exposed to extreme heat will be 14% compared to 37%;
• There will be one arctic sea ice free summer every 100 years compared to one at least every 10 years;
• 10-30% of existing coral reefs will survive compared to them completely disappearing;
• Global GDP losses will be 0.3% compared to 0.5% by 2100;
• A reduction in crop yields of maize will be 3% compared to 7%; 
• Plant species loss will be 8% compared to 16% and;
• 4.48 million km2 of permafrost will be lost compared to 6.6 million km2. 

There is a dramatic difference between the effect we will see at 1.5°C compared to 2°C of warming, with more extreme negative effects seen on communities, economies, and ecosystems with each fraction of additional warming. To limit these effects we must do all we can to limit warming to 1.5°C. This involves reducing CO2 emissions by 45% by 2030, and reaching net-zero global emissions by 2050.