The UN’s Intergovernmental Panel on Climate Change released its latest report last week, warning that failing to keep global warming below 1.5 degrees Celcius would result in hundreds of millions of deaths.
“Nearly all coral reefs would die out, wildfires and heat waves would sweep across the planet annually, and the interplay between drought and flooding and temperature would mean that the world’s food supply would become dramatically less secure,” New York Magazine noted.
In order to escape such a dire situation, the report said, a global effort to transform the world’s economy, agriculture and culture must be undertaken — an endeavor for which “there is no documented historical precedent.”
> Barring the arrival of dramatic new carbon-sucking technologies, which are so far from scalability at present that they are best described as fantasies of industrial absolution, it will not be possible to keep warming below two degrees Celsius — the level the new report describes as a climate catastrophe. As a planet, we are coursing along a trajectory that brings us north of four degrees by the end of the century. The IPCC is right that two degrees marks a world of climate catastrophe. Four degrees is twice as bad as that. And that is where we are headed, at present — a climate hell twice as hellish as the one the IPCC says, rightly, we must avoid at all costs.
What does a world at 2, 3 and 4 degrees of warming look like?
> At two degrees, the melting of ice sheets will pass a tipping point of collapse, flooding dozens of the world’s major cities this century. At that amount of warming, it is estimated, global GDP, per capita, will be cut by 13 percent. Four hundred million more people will suffer from water scarcity, and even in the northern latitudes heat waves will kill thousands each summer. It will be worse in the planet’s equatorial band. In India, where many cities now numbering in the many millions would become unliveably hot, there would be 32 times as many extreme heat waves, each lasting five times as long and exposing, in total, 93 times more people. This is two degrees — practically speaking, our absolute best-case climate scenario.
> At three degrees, southern Europe will be in permanent drought. The average drought in Central America would last 19 months and in the Caribbean 21 months. In northern Africa, the figure is 60 months — five years. The areas burned each year by wildfires would double in the Mediterranean and sextuple in the United States. Beyond the sea-level rise, which will already be swallowing cities from Miami Beach to Jakarta, damages just from river flooding will grow 30-fold in Bangladesh, 20-fold in India, and as much as 60-fold in the U.K. This is three degrees — better than we’d do if all the nations of the world honored their Paris commitments, which none of them are. Practically speaking, barring those dramatic tech deus ex machinas, this seems to me about as positive a realistic outcome as it is rational to expect.
> At four degrees, there would be eight million cases of dengue fever each year in Latin America alone. Global grain yields could fall by as much as 50 percent, producing annual or close-to-annual food crises. The global economy would be more than 30 percent smaller than it would be without climate change, and we would see at least half again as much conflict and warfare as we do today. Possibly more. Our current trajectory, remember, takes us higher still, and while there are many reasons to think we will bend that curve soon — the plummeting cost of renewable energy, the growing global consensus about phasing out coal — it is worth remembering that, whatever you may have heard about the green revolution and the price of solar, at present, global carbon emissions are still growing.
While the IPCC report said the effort needed to avoid these scenarios is unprecedented, some point to one effort in the past that could prove a useful model for approaching the present dilemma:
Other activists often see one precedent, in all of human history, citing the model of how the United States prepared for World War II, and calling for a global mobilization of that kind — all of the world’s rivalrous societies and nationalistic governments and self-interested industries organized around the common pursuit of a stable and comfortable climate as though warming was an existential threat.
> It is. And the World War II mobilization metaphor is not hyperbole. To avoid warming of the kind the IPCC now calls catastrophic requires a complete rebuilding of the entire energy infrastructure of the world, a thorough reworking of agricultural practices and diet to entirely eliminate carbon emissions from farming, and a battery of cultural changes to the way those of us in the wealthy West, at least, conduct our lives. And we need to do all of that in two, or possibly three, decades.
> That is not to say it’s over or we’re doomed. Stalling warming below four degrees is better than surpassing it, keeping temperatures below three is better still, and the closer we get to two degrees the more miraculous. That is because climate change isn’t binary, and doesn’t just kick in, full force, at any particular temperature level; it’s a function that gets worse over time as long as we produce greenhouse gases. How long we continue to is, really, up to us, which is to say it will be determined in the province of politics, which is to say public panic like that produced by the IPCC report can be a very productive form of policy pressure.