Greta Thunberg is a Swedish girl who, at age eight, learned that global climate change was a threat to humanity and other species. As a person who sees things in black and white, she is shocked that climate change is not everyone’s all-overriding concern. Humanity’s “house is on fire.” Her personal response, in 2018 at age fifteen, was to go on strike from school and stage a one-person protest in front of the Swedish Parliament. This solitary action also suited her personality. The resulting publicity made her a leading figure in worldwide protests against climate change.

According to the Intergovernmental Panel on Climate Change, an increase of more than 1.5 degrees Celsius in global temperatures by the year 2030 will most likely trigger a series of chain reactions that will result in irreversible damage to the planet’s climate. The damage will probably mean the end of civilization as we know it. Specific physical processes include feedback loops, due to things like methane being released by thawing Arctic permafrost. Some future warming is already locked in but is currently “hidden” by the sunlight-blocking effects of air pollution. 

The solution to the problem is simple, but radical: we must dramatically reduce greenhouse gas emissions by keeping fossil fuels in the ground. If we think in terms of a “carbon budget,” total emissions of 420 gigatons from 2018 to 2030 will give us a 67 percent chance of keeping the global temperature increase below 1.5 degrees. If global emissions are instead 580 gigatons over that same time period—that would essentially mean cutting emissions in half by 2030—then there is only a 50 percent chance of staying below the 1.5-degree limit. At that point, the end of human civilization comes down to a coin flip. Equity must be part of any plan that will work on a global scale. This means that most of the emissions cuts must be made by wealthier nations. Poorer nations must be given some opportunity to modernize their economies.

There is still time to solve the problem, but the time is fast running out. Thunberg constantly hears that she and other protesting schoolchildren should be in school, not traveling around lecturing policymakers. Her answer to this complaint is simple: if people want to ignore her and the other children, that is fine. But pay attention to the facts. Listen to the scientists.