Three degrees C hotter (since 1988)
The hottest temperature ever claimed on earth was 136 o Fahrenheit (58 o Celsius) in the Libyan desert in 1922, though this figure is of course disputed. The “agreed-on” record is currently held by the United States where the summer temperature reached 134.1o (56.7o Celsius) at Furnace Creek in Death Valley on July 10, 1913. However, according to measurements taken by [somebody’s] satellite between 2003 and 2009, temperatures at Dasht-e Lut, an uninhabited desert region in Iran, reached a staggering 159 o Fahrenheit (70.7 o Celsius). Most unprotected living things die quickly at all such temperatures.
In the United States, not long after the earth’s average annual worldwide temperature has increased by 3o Celsius, Houston will lead our Gulf cities by experiencing a summer daytime high of 147 o Fahrenheit (o 63.8 Celsius). As air conditioners fail all over the city, hundreds will die quickly from the inescapable heat. Doubts about the reality of global warming will be firmly, finally ended, but the self servers who promulgated the phony doubts will by then be peacefully dead, the horrendous consequences of their selfish crime against humanity far beyond any conceivable reversal as electric power sources fail and humanity steadily loses its struggle with nature’s natural consequences.
The super-hurricane era introduced by Katrina will take up residence in earnest on the U.S. Gulf coast, every new storm further diminishing the coastline, destroying wetlands and productive fields, trashing homes and infrastructure so thoroughly that it becomes infeasible to even try to restore them in the re-shaped conditions. The peoples of southern Texas, Alabama, Georgia, Florida and, especially, Louisiana will leave en masse the place they called home for generations and flee northward in quest of an environment they can survive in. Further inland, away from the coast, deluges of rainfall will give but temporary respite from droughts that extend and grow longer every year. Corn and wheat, already at their thermal tolerance threshold in the overheated south, will be hardest hit.
Sometime in the second half of the 21st century the giant plumbing system called the Colorado River will fail repeatedly, the catastrophe worsening with each failure. Western farmers and cities will be pumping the remaining aquifers dry at the same time that runoff from snowmelt declines every year toward its inevitable termination. There are simply too many people living in the arid western states, all too dependent on the old river’s declining water. The range over which food crops can be planted with expectation of viable, profitable return will move further northward every year. The people leaving to move north will represent an entire latitudinal belt reaching fully around the globe.
Growing food deficits will drive prices higher across the USA every year. Arbitrary price controls will be tried yet again simply because so many Americans with low or no income can no longer afford even rudimentary life basics of food, clothing and shelter.
The New York City-Newark-Jersey City metro area, with over 20 million people, has some 1,500 miles of coastline. Most of this coastal area is very low-lying, with thousands of apartment blocks, bridges, roads, railroads and tunnels barely above, at, or below sea level. Four of the city’s five boroughs are islands. Surrounding sea levels are right now, today, ten inches higher than they were a century ago in 1920.
At three degrees increase in world temperature, sea level in the metro area will rise up to three feet more at an accelerating rate that depends, unknowably, on how fast the Greenland and Antarctic ice caps melt. As regular high tides combine with periodic storm surges, lower Manhattan, Coney Island, Jersey City and Hoboken along with La Guardia and Newark international airports will be inundated on average every five years, their entire areas becoming economically unviable. Business and residential inhabitants of these New York metro areas will have no choice but to abandon them and move farther inland if not away from the region altogether.
At 395 feet tall and weighing 450,000 pounds, the Statue of Liberty—if it does not itself lean and fall—will increasingly welcome arrivals to little more than a fast-eroding coastline backed by the ruins of skyscrapers that topple, one by one, as sea water intrudes underground and destabilizes their foundations. Few will remember that the tiny island Liberty stands on was mostly underwater during superstorm Sandy back in the year 2012.
Around the world: Southern Africa will present special problems as drought spreads and intensifies across the region. With the Indian Ocean warming faster than other world oceans—as it indeed is already doing—its torrential rains will dump much of their vital moisture uselessly back into the ocean before reaching the coast. Moisture will have been wrung out of the air that eventually flows across southern African fields. Africa’s entire southern half will become increasingly dry as ever more of its rainfall is lost in this way, accompanied of course by greatly diminished ability to grow food crops. Wildlife increasingly will disappear, poached from the great African plains by starving people.
Southern Africa’s vast stabilized dune fields look like gently rolling grass-covered landforms, but like the American high plains, they aren’t. These grass-covered northern and eastern extensions of the Kalihari desert—extending across Zambia, Angola, Namibia, Botswana, western Zimbabwe and down into northern South Africa—are today home to millions of people who reside and make a living there. The dune fields will steadily destabilize as heat kills the grass and raging sandstorms like those that built them thousands of years ago become reality once again. As the bone-dry western Kalihari reclaims its full ancient range, all these people will simply have nowhere to go.
Fully half our world’s precious biodiversity lives in the rainforests of Amazonia, Indonesia and Malaysia. Unknown to most people, these vast ecosystems are underlain by colossal beds of moist peat, accumulated over thousands of years and over a hundred feet thick in places. They store vast amounts of the planet’s excess carbon, and are stable only so long as they remain waterlogged.
These rainforests are now being destroyed at catastrophic rates—hundreds of square miles each year—by profiteers whose impoverished work crews log off, bulldoze and burn the remaining trees to create cleared ground for grazing cattle and monoculture palm oil plantations. Not only do these clearings release the vast carbon stored in the trees and undergrowth, the underlying peat thus exposed to tropical heat dries out and releases additional billions of tons of stored carbon. Adding to calamity, fires set by lightening and deliberately by workers burn far down to unquenchable depths into the deep peat, releasing further billions of tons.
These species-suicidal travesties are merely what’s going on today. Since it is the extensive range of the rainforests themselves that generate much of the rainfall that gives them their name, their diminishing size means that dry season rainfall in all three areas will undergo major declines by the time worldwide average temperature reaches three degrees of warming. No longer tenable for grazing, plantations or indeed most kinds of agriculture, the depleted areas will further suffer from droughts that come more often and stay longer. The lost rainforests and the life value they represented would not have been able to soon regenerate themselves even in the absence of the excessive new heat.
Excessive drought and explosive rains are society killers, and both extremes are now growing in expanding areas around the world. Three degrees of heat increase will be particularly devastating for all of subtropical central America, which has been identified as a climate change “hot spot” of greatest concern in a warming world. Large areas of southern Mexico have been denuded of their tree cover, and from there through central America each new hurricane brings hillside erosion, destroying farmland needed to feed the burgeoning population, while massive flooding and mudslides are becoming common throughout the region. Whereas a moderate drought in 2001 left a million and a half people dependent on food aid for several months, in a three-degree world where food supplies are already thin and in enormous demand, such aid simply will not come.
Four degrees C hotter (since 1988)
In the United States, an average temperature increase of four degrees will see rising sea levels inundating downtown business districts along our overpopulated east coast from Boston down to New Jersey, including most of Jersey’s densely populated coastal areas. For millions of Americans from there to Florida, the only available option will be to move inland—where soaring land and housing prices will be prohibitive for an increasing percentage of the U.S. population. Even where governments of coastal urban areas are willing to tax for the enormous costs to rebuild, insurers will refuse to issue policies where the odds for survival of a rebuilt city are so poor and worsening yearly.
Inland cities will be trying to cope with constant arrival of thousands of coastal refugees—a flow that will swell to millions after each new mega-hurricane, making the Katrina refugee crisis look like a tea party for the few who remember. As economic shocks cascade through the financial system, social stability and public confidence in the “emergency savior value” of governments at any level will suffer accordingly. The loss of fine old buildings and birthplaces of famous citizens, treasured symbols of American history, will be mourned briefly by those with the luxury of time to do so.
At four degrees of temperature increase, mountain heights across our Rockies, Sierra Nevada and associated western ranges, treasured for their scenic vistas, invaluable glaciers and snowpack, will feature hot bare rock. Almost all their traditional flora and fauna will no longer live there; many will no longer be alive anywhere at all.
The estimated consequences of four degrees warming, as conjectured in the last three paragraphs, are in my opinion grossly understated in the science-based sources, credible and varied, from which I drew and merged them. My opinion in this regard is based on the following planet-wide conjectures from the same or comparable scientific sources.
Around the world: The last time the earth was at the temperature we will be when we’re four degrees warmer—40 million years ago—there was no ice at either of earth’s poles. In consequence of that, sea levels around the earth in those old days were about 220 feet higher than they are today. A lot of landforms can change in 40 million years, so we cannot be certain that melting all the polar ice in this century and next will result in the same 220 feet of sea level rise—for sure, though, it won’t be all that different. Maybe it will rise only 205 feet.
Consider. Earth’s great ice caps are huge. The one on Greenland—three times the size of Texas—is 1,500 miles long and 680 miles wide, with a thickness ranging 6,600 feet (well over a mile) to 9,800 feet (the better part of two miles). It contains about 600,000 cubic miles of ice, making it the second-largest structure on earth; it is, nevertheless, the smaller of earth’s two ice caps. The big one is on Antarctica, where 7.2 million cubic miles of frozen water cover all but two percent of the Antarctic continent. Its 5.4 million square-mile area is roughly the size of the U.S. and Mexico combined.
This largest structure on earth averages over 7,000 feet thick, and at its thickest point is 15,669 feet (just under three miles) deep. Antarctica’s ice represents about 90 percent of all ice on earth. When it melts, this one big ice cap alone will raise world oceans nearly 200 feet. On our present trajectory, that is not if, it’s when. At this writing Antarctica’s rate of melting is about 24 cubic miles per year. Most alarmingly, the speed of melting has tripled over the past 25 years—far beyond scientist’s projections—and much of that acceleration occurred in the past five years alone.
The three trillion tons of ice that melted between 1992 and 2017 represent about 8 millimeters of sea level rise. Eight millimeters sounds small, but it is hugely significant when multiplied by the surface area of all world oceans onto which it has been added. That “mere” 8 millimeters translates to about 0.31 inches of water depth. Now, to gain a barest glimmer of understanding as to the vast amount of fresh water that has already been added to the world’s oceans, multiply that deceptively “small” 0.31 inches times the 140 million-square-mile continuous surface area of the oceans that cover almost three-fourths of the earth’s surface. Nature can do a lot with that much new water.
By the time earth’s four-degree temperature rise has done its work on worldwide sea-level rise, the Nile delta will be submerged, lovely ancient Alexandria submerging along with it, the heart of Egypt’s economy going down with them. One-third of Bangladesh’s land area will be underwater. All island nations will be gone, as will Florida. In China and India, if agriculture does not collapse altogether, staple crops will be reduced by half or more, and those venerable ancient nations’ huge populations will find ways to express their deep concerns and displeasure over the inadequacy of available food. In Pakistan, Sudan and other places between Morocco and Thailand, things will be worse.
Human refugees will be everywhere, mainly on foot, seeking relief in all directions. At four degrees increased heat, melting Arctic permafrost will release somewhere between 500 and 900 billion additional tons of carbon dioxide and, worse, unmeasaurable methane into our already overheated atmosphere above the Arctic circle, belting the northern hemisphere. It is to be noted that a mere one percent (1%) of 900 billion tons is double the amount of humanity’s CO2 emissions here in the early 21st century. No one—no one—is really sure whether our species could survive the resulting devastation.
What do you think the new continental and island coastlines will look like after the oceans have risen more than 200 feet around the world? Google on “coastlines after 200 foot ocean rise” for a reasonably good-enough preview. But the whole 200 feet may take longer than is expected, possibly more than two centuries directly ahead. We might get only ten to twenty feet by the end of this century, depending on whether we succeed in slowing down global warming. Do you think we humans, all of us, have the moxie to halt, and reverse, our discharge of carbon dioxide that is causing global warming? Did you know that we’re pretty much already committed, right now, to around nine to twelve feet of sea level rise just from the global warming that’s already unstoppably in the pipeline? You didn’t? All these things are what hard science says, and having closely followed the best science available for years, I think they’re right. What do you think?