Commentary: The consensus of scientific evidence has for at least 50 years supported climate change arising from human action. Yet, the world generally and the United States particularly has failed to adopt adequate measures to mitigate greenhouse gas admission. We now stand at the brink and urgent action is necessary. Action on climate change is the greatest challenge to public policy of our time.
Atmospheric concentrations of carbon dioxide, the primary greenhouse gas, are now over 400 parts per million. The last time carbon was this concentrated was 3 million years ago. Global temperatures were 3-degrees C higher; sea levels were 10 to 20 meters above today’s level. Meanwhile, the human species is only 250,000 years old. And agriculture has been practiced for about 10,000 years.
The entire history of homo sapiens has seen variation in temperature variation of only plus-or-minus 1-degree C. The world is now on the edge of that experience. We are already seeing considerable stress to the global economic system arising form climate change. Yet we continue to add to global carbon dioxide concentrations at a rate of 2 parts per million per year.
A UN report released in October of last year makes stark the costs of further warming. At 1.5-degrees C of warming, the current UN set target, the impact is substantial: storms are more powerful; oceans more acidic; whole sections of landmasses transform from one ecosystem to another; species extinction accelerates. An extra one-half degree of warming from 1.5-degrees C to 2-degrees C would double the length of droughts, the occurrence of extreme weather events would more than double, and that coral would disappear.
The cost of delayed action is substantial. For example, a study conducted by a group led by Harvard’s Jason Furman found that a 10-year delay in adoption of policies aimed at reducing greenhouse gas emission, increased costs 39%, meaning that action now will reduce overall cost of climate change. A second conclusion from Furman’s group is that the more ambiguous the climate target, the greater is the cost of delay.
Unfortunately, the world is in a sort of prisoners’ dilemma when it comes to climate action. Greenhouse gases are globally mixing pollutants; an emission anywhere in the world has the same impact on global climate. Jurisdictions that take climate action face the risk of “leakage”, meaning that local reduction in greenhouse gases is offset by increased greenhouse gas emissions in other unregulated jurisdictions.
Thus, uncoordinated local action has no net global impact. Ambitious legislation passed last session by the New Mexico legislature to require that the state’s public utilities to be carbon-free by 2045 is subject to this problem.
To be effective, climate action must be globally coordinated. To achieve the current proposed target of no more than 1.5-degrees C of warming requires that each nation set aggressive carbon targets and enforce those targets.
The call to action is being led by children with school strikes for climate underway, involving millions of children globally. The speech at the UN during the recent Climate Week by youth activist Greta Thunberg vividly laid the blame on the current generation. Let’s take up the challenge given us by the young. We need coordinated global action.
Christopher A. Erickson, Ph.D., is a professor of economics at NMSU. He was originally a climate skeptic, but faced with growing evidence that he was wrong, he changed his mind. The opinions expressed may not be shared by the regents and administration of NMSU. Chris can be reached at chrerick@nmsu.edu.