New Climate Change Impact Forecast: Massive, Drastic, Inescapable — But (Not Necessarily) Apocalyptic

The New World: Envisioning Life After Climate Change 


By David Wallace-Wells

New York Times — 10/28/2022

Climate change has led to roughly 1.2 degrees Celsius of warming so far, making the earth hotter now than it has ever been in the long history of civilization. . . .

We know what put us in this predicament: more than one trillion tons of carbon produced by human activity now suspended in our atmosphere.

That’s as much as the total mass of every human-built structure and object on earth. . . .

Not very long ago, scientists warned that this could cause four or five degrees Celsius of warming, giving rise to existential fears about apocalyptic futures.

But in just the past few years, the future has begun to look somewhat different, thanks to a global political awakening, an astonishing decline in the price of clean energy, a rise in global policy ambition and revisions to some basic modeling assumptions.

When scientists talk about the path we’re on today, they are often referring to warming between two and three degrees Celsius, or between 3.6 and 5.4 degrees Fahrenheit — a little more than half as much as was projected to be the “business as usual” future a
decade ago. The United Nations confirmed that range in a report released this week.

To stabilize the world’s temperatures at the cooler end of that range, two degrees, will require a near-total transformation of all the human systems that gave rise to warming: energy, transportation, agriculture, housing and industry and infrastructure. But, while ambitious and difficult, it now seems possible — a very different sort of future, neither a best-case nor a worst-case scenario.

Though it would mean environmental upheaval and climatic disruption unprecedented in the long sweep of human history, this is a more hopeful outcome than many dared to believe less than a decade ago. It is also much harsher than many had hoped for.

What follows is a partial, hopscotching geography of the jagged new world that climate change is making. As much as our planet has already been transformed by climate change, it will be transformed far more in the decades to come. . . .

Many of these spillovers may have limited effects. But there will be thousands more of them . . . .

Covid-19 has given us a sense of how disruptive just one global pandemic can be, but a new “pandemicine” could deliver several at once. . . .

In the next half century, it’s projected that there will be at least 4,000 new spillover events, as viruses cross from one animal species to another, including to humans — because of migrations of wildlife, which will roughly double the number of first encounters among species compared with today. . . .

Everything will move — ecosystems, too. At two degrees, according to one study, more than 10,000 plant species would lose half their habitable area. Every place in every part of the world would essentially trade its current climate for a hotter one:

One study projected a change for European cities that was the equivalent of moving about 600 miles toward the Equator, or about a dozen miles each year. . . .

Wildfires will be much more common in Europe, and in London, where summers are already turning the foliage wilted and brown,

In the United States, extreme heat will stretch from Texas and Louisiana up through the Midwest, where by the mid-2050s, a report from the First Street Foundation suggests, more than 100 million Americans would be experiencing at least one 125-degree day each summer. According to another report, moving from 1.5 to 2 degrees would mean the number of people experiencing a severe heat wave at least once every five years would roughly triple worldwide.

These temperature shifts will mean enormous relocations of animal life, mostly away from the Equator and toward the poles.

Already, according to the Intergovernmental Panel on Climate Change, more than half of all assessed species have shifted their habitats poleward in response to warming. . . .

Humans will move, too. The I.P.C.C. estimates that more than three billion people live today in places “highly vulnerable” to climate change. How many will move? How many will adapt? How many will suffer?

The range of estimates is huge, a sign of how much uncertainty about human response hangs over everything we think we know about the climate future.

Some studies suggest, at two degrees, that there will be tens of millions of climate migrants. Others, hundreds of millions.

Regardless of the figure, mass climate migrations will become a fact of life

This is why the writer Gaia Vince called her new book “Nomad Century.” In it, she argues that climate migration doesn’t have to look like refugee camps and border walls.

It could work, she says, like a humane system — extending citizenship rights and effectively promoting, amid the tragedy of abandoned homelands, overall human flourishing.

But a bleaker future might be easier to imagine: harder borders, a more restrictive global migration regime and the continued rise of nativist politicians fanning fears of increasing immigration.

If there is one thing to know about the world at two degrees — or even the world today, at 1.2 degrees — it is that warming is unjust. The rainfall that led to Pakistan’s historic monsoon flooding this year was made 50 percent worse by climate change, by one estimate, even though the country has contributed in all its industrial history only as much carbon to the atmosphere as the United States does each and every year.

And though the future will be hard everywhere, wealth will enable many places to adapt. In some places, life could even grow more pleasant — as the end of fossil fuels also eliminates the millions of premature deaths caused each year by burning them. Cities may turn increasingly away from cars and toward biking and green space.

Rich nations may be able to make investments in flood systems, hardier infrastructure and whole new water-management regimes like large-scale desalination projects to turn seawater into drinking water. . . .

In some cities, there will be new cooling infrastructure, ranging from the “natural” (e.g., more tree cover) to the obvious (“cool” roofs, smaller windows, new pavements) to the somewhat strange (water misting from bus stops and store awnings) and even Rube Goldberg-like (water canals under city blocks to create underground air-conditioning).

The construction project that lies ahead is vast — nearly everything about our built environment will need at least an upgrade and in many cases will have to be totally reimagined. This is a burden but also, for some, an opportunity. One report by McKinsey estimated that, in some scenarios, a transition to net zero emissions could generate more than $12 trillion in annual revenue gains, and not just for solar entrepreneurs. The biggest “value pool” they identified was transportation; the second biggest, buildings.

It is a perverse reality that the nations positioned to manage best, adapting most successfully to their new ecosystems, are likely to be the same nations responsible for most of the world’s carbon output.

The United States is responsible for about a fifth of all historical emissions, many of which hang in the air for centuries and are still heating the planet now.

The average American today creates 200 times as much carbon pollution as the average person living in Congo, Somalia, Ethiopia or Niger. . . .

Africa is the continent where much of the global population growth this century will take place — and where, between droughts and heat waves and hunger, the climate impacts are likely to be cruelest. . . .

In the hotter parts of the world, it will become increasingly dangerous to go outside during parts of the year, trapping residents indoors during many hours of the day. Outdoor labor during the middle of the day might become nearly impossible in some seasons.

According to the African Development Bank, the continent is already losing up to 15 percent of its economic growth because of climate change. Globally, according to some research, at just over one degree of temperature rise, climate change may already have worsened global income inequality by as much as 25 percent. At two degrees, those impacts would be magnified even more.

Oceans, which cover more than 70 percent of the planet, will be transformed.

In the new world, there will be, to a rough approximation, zero living coral reefs.

You may think of this merely as a blow to scuba tourism — but in fact, food harvested directly from corals supplies protein for hundreds of millions of people today.

And something like a quarter of all global ocean biodiversity depends on reefs, all of which are now believed to be imminently endangered. . . .

But as bad as all that is, the biggest questions about the oceans are: How high will they rise, and how fast?

The range of expected sea-level elevation by the end of this century, at two degrees, is quite large: The I.P.C.C. has given a median projection of just 47 centimeters [18.5 inches, or 1.5 feet], though other estimates are several multiples of that.

And sea levels are an area where, even in more optimistic scenarios about future emissions, scientists worry about “tipping points” — that just two degrees of warming might trigger a feedback loop in the Greenland and Antarctic ice sheets that can’t be reversed.

Greenland alone contains enough ice to raise sea levels by more than 20 feet; the Antarctic, considerably more. But little of that melt would come this century. (Already, tens of billions of tons of ice are melting into the oceans every year, but given the size of the planet, the rate feels slow.)

Perhaps the most striking feature of sea-level rise is that we know that it will never stop — the water will only keep rising, forever.

What about food? At two degrees of warming, yield declines are expected for most staple crops. By one estimate, roughly 40 percent of today’s cropland is expected to experience severe drought at least three months a year by 2050. . . .

Even at two degrees of warming, though, mass starvation isn’t inevitable. Innovations — from new seeds to new fertilizer and new farming methods and new croplands — could at least soften the impact, or perhaps extend the yield gains of the past decades into even a hotter future.

Of course, the question of adaptation and innovation is not a theoretical one. Warming has already pushed many millions of people close to starvation today.

Weather disasters won’t just be more intense; they will also be more frequent. . . .

At two degrees, what are now once-in-a-decade heat waves would be expected more than five times as frequently, and over a third of the world’s population would be hit with severe heat waves once every five years.

Think of the Australian bushfire season of 2019-20, known as the Black Summer, which is estimated to have killed some three billion animals; it blanketed Sydney Harbor with so much smoke that ferries couldn’t run, and the fire alarms in office buildings were set off by the ambient smoke.

At two degrees, events like that would be far more likely to occur — and reoccur.

In India, by century’s end, there could be 30 times as many severe heat waves as today, lasting five times as long on average. . . .

A storm worse than Hurricane Sandy could happen every five years, and along the coast, “hundred-year floods” could happen as often as every single year. There could simply be no time to recover, particularly when one climate extreme coincided with another “compounding event.”. . .

The biggest human response will be in power generation. Currently, more than 80 percent of the world’s energy production still comes from fossil fuels. To limit temperature rise to two degrees, it would probably have to fall all the way to zero in the next five decades — if not faster.

As much as 10 percent of the landmass of the United States could be marshaled to produce electricity from wind and solar.

Other estimates put the figure at up to 1 percent of the country — the size of Maine. Whatever the area, it’s a shift that would require unprecedented battles over land use, environmental review and eminent domain.

The federal government has set a goal to expand offshore wind power almost a thousandfold by 2030, to 30,000 megawatts from just 42 megawatts — meaning long lines of turbines along stretches of the American coast.

The energy revolution will be even more transformative elsewhere in the world, where hundreds of millions of people today lack access to electricity — and could acquire it not by burning coal and oil and gas but through the solar and wind power they already have in abundance.

The explosion of this new energy infrastructure will make the new world look radically different from ours. We don’t know the exact mix — wind and solar are the intuitive choices today, but they may be supplemented or even supplanted by green hydrogen, geothermal or next-generation nuclear.

A renewables revolution like this will also require a mining revolution and an entirely new extractive economy. It has been estimated that demand for lithium, the mining of which is necessary for electric-vehicle batteries, will grow eightfold by 2030.

Already, projects are planned to drill for minerals at the deepest parts of the ocean floor, and China, which dominates the lithium refinement market, is exploring the possibility of sourcing critical elements from the moon.

It is easy to feel overwhelmed by this vision of the coming world. This is a world in which all our systems of energy, transportation, industry and infrastructure will have to be remade in just decades.

But less than a decade ago, the world that lay ahead seemed even more disastrous than the one we’ve just taken a tour of; truly apocalyptic scenarios for all of humanity seemed plausible. Today we are faced with something different: climate upheaval big enough to terrify and intimidate and yet open-ended enough to be wrangled and even managed by politics and human design, as well.

That’s because, as we have seen, climate impacts represent only half the story. The other half is human response — how we manage those impacts and build a future beyond and around them.

We have lost our chance to forestall disaster, and there are reasons to fear the world to come.

But it remains ours to make.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.