The world seems to be in a state of permanent crisis. The liberal international order is besieged from within and without. Democracy is in decline. A lackluster economic recovery has failed to significantly raise incomes for most people in the West. A rising China is threatening U.S. dominance, and resurgent international tensions are increasing the risk of a catastrophic war.
Yet there is one threat that is as likely as any of these to define this century: climate change. The disruption to the earth’s climate will ultimately command more attention and resources and have a greater influence on the global economy and international relations than other forces visible in the world today. Climate change will cease to be a faraway threat and become one whose effects require immediate action.
The atmospheric concentration of carbon dioxide, the main greenhouse gas, now exceeds 410 parts per million, the highest level in 800,000 years. Global average surface temperatures are 1.2 degrees Celsius higher than they were before the Industrial Revolution. The consensus scientific estimate is that the maximum temperature increase that will avoid dangerous climate change is two degrees Celsius. Humanity still has around 20 years before stopping short of that threshold will become essentially impossible, but most plausible projections show that the world will exceed it.
Two degrees of warming is still something of an arbitrary level; there is no guarantee of the precise effects of any temperature change. But there is a huge difference between two degrees of warming and two and a half, three, or four degrees. Failing to rein in global emissions will lead to unpleasant surprises. As temperatures rise, the distribution of climate phenomena will shift. Floods that used to happen once in a 100 years will occur every 50 or every 20. The tail risks will become more extreme, making events such as the 50 inches of rain that fell in 24 hours in Hawaii earlier this year more common.
Making climate change all the more frightening are its effects on geopolitics. New weather patterns
Loading, please wait...