My Doomsday religion is still Judaism.
"Since it is going to take so long man will adapt over the long period of time"
According to NOAA, carbon dioxide accumulated by 3.03 parts per million during 2015 and by 3.00 parts per million during 2016. These now represent the two fastest rates of carbon dioxide accumulation in the climate record to date. By comparison, the substantial warming at the end of the last ice age was accompanied by an approximate 0.01 part per million per year rate of CO2 increase averaged over 10,000 years.
"it is not so bad. Probably be a good thing."
This is a bit old; I think it first appeared in '06. There is now some evidence that a few of the feedbacks the author talks about are already occuring. I've marked them with an *, cuz it's not just your* it's the grandkids*,too.
BETWEEN TWO AND THREE DEGREES OF WARMING
Up to this point, assuming that governments have planned carefully and farmers have converted to more appropriate crops, not too many people outside subtropical Africa need have starved. Beyond two degrees, however, preventing mass starvation will be as easy as halting the cycles of the moon. First millions, then billions, of people will face an increasingly tough battle to survive.
To find anything comparable we have to go back to the Pliocene – last epoch of the Tertiary period, 3m years ago. There were no continental glaciers in the northern hemisphere (trees grew in the Arctic), and sea levels were 25 metres higher than today’s. In this kind of heat, the death of the Amazon is as inevitable as the melting of Greenland. The paper spelling it out is the very one whose apocalyptic message so shocked in 2000. Scientists at the Hadley centre feared that earlier climate models, which showed global warming as a straightforward linear progression, were too simplistic in their assumption that land and the oceans would remain inert as their temperatures rose. Correctly as it would turn out, they predicted positive feedback.
Warmer seas absorb less carbon dioxide, leaving more to accumulate in the atmosphere and intensify global warming. On land, matters would be even worse. Huge amounts of carbon are stored in the soil, the half-rotted remains of dead vegetation. The generally accepted estimate is that the soil carbon reservoir contains some 1600 gigatonnes, more than double the entire carbon content of the atmosphere. As soil warms, bacteria accelerate the breakdown of this stored carbon, releasing it into the atmosphere.
The end of the world is nigh. A three-degree increase in global temperature – possible as early as 2050 – would throw the carbon cycle into reverse. Instead of absorbing carbon dioxide, vegetation and soils start to release it. * So much carbon pours into the atmosphere that it pumps up atmospheric concentrations by 250 parts per million by 2100, boosting global warming by another 1.5C. In other words, the Hadley team had discovered that carbon-cycle feedbacks could tip the planet into runaway global warming by the middle of this century – much earlier than anyone had expected.
Confirmation came from the land itself. Climate models are routinely tested against historical data. In this case, scientists checked 25 years’ worth of soil samples from 6,000 sites across the UK. The result was another black joke. As temperatures gradually rose the scientists found that huge amounts of carbon had been released naturally from the soils. They totted it all up and discovered – irony of ironies – that the 13m tonnes of carbon British soils were emitting annually was enough to wipe out all the country’s efforts to comply with the Kyoto Protocol.” All soils will be affected by the rising heat, but none as badly as the Amazon’s. “Catastrophe” is almost too small a word for the loss of the rainforest. Its 7m square kilometres produce 10% of the world’s entire photosynthetic output from plants. Drought and heat will cripple it; fire will finish it off. In human terms, the effect on the planet will be like cutting off oxygen during an asthma attack.
In the US and Australia, people will curse the climate-denying governments of Bush and Howard. No matter what later administrations may do, it will not be enough to keep the mercury down. With new “super-hurricanes” growing from the warming sea, Houston could be destroyed by 2045, and Australia will be a death trap. “Farming and food production will tip into irreversible decline. Salt water will creep up the stricken rivers, poisoning ground water. Higher temperatures mean greater evaporation, further drying out vegetation and soils, and causing huge losses from reservoirs. In state capitals, heat every year is likely to kill between 8,000 and 15,000 mainly elderly people.
It is all too easy to visualise what will happen in Africa. In Central America, too, tens of millions will have little to put on their tables. Even a moderate drought there in 2001 meant hundreds of thousands had to rely on food aid. This won’t be an option when world supplies are stretched to breaking point (grain yields decline by 10% for every degree of heat above 30C, and at 40C they are zero). Nobody need look to the US, which will have problems of its own. As the mountains lose their snow, so cities and farms in the west will lose their water and dried-out forests and grasslands will perish at the first spark.
The Indian subcontinent meanwhile will be choking on dust. All of human history shows that, given the choice between starving in situ and moving, people move. In the latter part of the century tens of millions of Pakistani citizens may be facing this choice. Pakistan may find itself joining the growing list of failed states, as civil administration collapses and armed gangs seize what little food is left.
As the land burns, so the sea will go on rising. Even by the most optimistic calculation, 80% of Arctic sea ice by now will be gone, and the rest will soon follow. New York will flood; the catastrophe that struck eastern England in 1953 will become an unremarkable regular event; and the map of the Netherlands will be torn up by the North Sea. Everywhere, starving people will be on the move – from Central America into Mexico and the US, and from Africa into Europe, where resurgent fascist parties will win votes by promising to keep them out.
Chance of avoiding three degrees of global warming: poor if the rise reaches two degrees and triggers carbon-cycle feedbacks from soils and plants*.
BETWEEN THREE AND FOUR DEGREES OF WARMING
The stream of refugees will now include those fleeing from coasts to safer interiors – millions at a time when storms hit. Where they persist, coastal cities will become fortified islands. The world economy, too, will be threadbare. As direct losses, social instability and insurance payouts cascade through the system, the funds to support displaced people will be increasingly scarce. Sea levels will be rampaging upwards – in this temperature range, both poles are certain to melt, causing an eventual rise of 50 metres. “I am not suggesting it would be instantaneous. In fact it would take centuries, and probably millennia, to melt all of the Antarctic’s ice. But it could yield sea-level rises of a metre or so every 20 years – far beyond our capacity to adapt.Oxford would sit on one of many coastlines in a UK reduced to an archipelago of tiny islands.
More immediately, China is on a collision course with the planet. By 2030, if its people are consuming at the same rate as Americans, they will eat two-thirds of the entire global harvest and burn 100m barrels of oil a day, or 125% of current world output. That prospect alone contains all the ingredients of catastrophe. But it’s worse than that: “By the latter third of the 21st century, if global temperatures are more than three degrees higher than now, China’s agricultural production will crash. It will face the task of feeding 1.5bn much richer people – 200m more than now – on two thirds of current supplies.” For people throughout much of the world, starvation will be a regular threat; but it will not be the only one.
The summer will get longer still, as soaring temperatures reduce forests to tinderwood and cities to boiling morgues. Temperatures in the Home Counties could reach 45C – the sort of climate experienced today in Marrakech. Droughts will put the south-east of England on the global list of water-stressed areas, with farmers competing against cities for dwindling supplies from rivers and reservoirs.
Air-conditioning will be mandatory for anyone wanting to stay cool. This in turn will put ever more stress on energy systems, which could pour more greenhouse gases into the air if coal and gas-fired power stations ramp up their output, hydroelectric sources dwindle and renewables fail to take up the slack. The abandonment of the Mediterranean will send even more people north to “overcrowded refuges in the Baltic, Scandinavia and the British Isles.
Britain will have problems of its own. As flood plains are more regularly inundated, a general retreat out of high risk areas is likely. Millions of people will lose their lifetime investments in houses that become uninsurable and therefore unsaleable? The Lancashire/Humber corridor is expected to be among the worst affected regions, as are the Thames Valley, eastern Devon and towns around the already flood-prone Severn estuary like Monmouth and Bristol. The entire English coast from the Isle of Wight to Middlesbrough is classified as at ‘very high’ or ‘extreme’ risk, as is the whole of Cardigan Bay in Wales.
One of the most dangerous of all feedbacks will now be kicking in – the runaway thaw of permafrost.* Scientists believe at least 500 billion tonnes of carbon are waiting to be released from the Arctic ice, though none yet has put a figure on what it will add to global warming. One degree? Two? Three? The pointers are ominous.
As with Amazon collapse and the carbon-cycle feedback in the three-degree worldstabilising global temperatures at four degrees above current levels may not be possible. If we reach three degrees, therefore, that leads inexorably to four degrees, which leads inexorably to five?
Chance of avoiding four degrees of global warming: poor if the rise reaches three degrees and triggers a runaway thaw of permafrost*.
BETWEEN FOUR AND FIVE DEGREES OF WARMING
We are looking now at an entirely different planet. Ice sheets have vanished from both poles; rainforests have burnt up and turned to desert; the dry and lifeless Alps resemble the High Atlas; rising seas are scouring deep into continental interiors. One temptation may be to shift populations from dry areas to the newly thawed regions of the far north, in Canada and Siberia. Even here, though, summers may be too hot for crops to be grown away from the coasts; and there is no guarantee that northern governments will admit southern refugees. Lynas recalls James Lovelock’s suspicion that Siberia and Canada would be invaded by China and the US, each hammering another nail into humanity’s coffin. Any armed conflict, particularly involving nuclear weapons, would of course further increase the planetary surface area uninhabitable for humans.
When temperatures were at a similar level 55m years ago, following a very sudden burst of global warming in the early Eocene, alligators and other subtropical species were living high in the Arctic. What had caused the climate to flip? Suspicion rests on methane hydrate – “an ice-like combination of methane and water that forms under the intense cold and pressure of the deep sea”, and which escapes with explosive force when tapped. Evidence of a submarine landslide off Florida, and of huge volcanic eruptions under the North Atlantic, raises the possibility of trapped methane – a greenhouse gas 20 times more potent than carbon dioxide – being released in a giant belch that pushed global temperatures through the roof.
Summer heatwaves scorched the vegetation out of continental Spain, leaving a desert terrain which was heavily eroded by winter rainstorms. Palm mangroves grew as far north as England and Belgium, and the Arctic Ocean was so warm that Mediterranean algae thrived. In short, it was a world much like the one we are heading into this century. Although the total amount of carbon in the atmosphere during the Paleocene-Eocene thermal maximum, or PETM, as scientists call it, was more than today’s, the rate of increase in the 21st century may be 30 times faster. It may well be the fastest increase the world has ever seen – faster even than the episodes that caused catastrophic mass extinctions.
Globalism in the five-degree world will break down into something more like parochialism. Customers will have nothing to buy because producers will have nothing to sell. With no possibility of international aid, migrants will have to force their way into the few remaining habitable enclaves and fight for survival.
Where no refuge is available, civil war and a collapse into racial or communal conflict seems the likely outcome. Isolated survivalism, however, may be as impracticable as dialling for room service. How many of us could really trap or kill enough game to feed a family? Even if large numbers of people did successfully manage to fan out into the countryside, wildlife populations would quickly dwindle under the pressure. Supporting a hunter-gatherer lifestyle takes 10 to 100 times the land per person that a settled agricultural community needs. A large-scale resort to survivalism would turn into a further disaster for biodiversity as hungry humans killed and ate anything that moved. Including, perhaps, each other. Invaders do not take kindly to residents denying them food. History suggests that if a stockpile is discovered, the householder and his family may be tortured and killed. Look for comparison to the experience of present-day Somalia, Sudan or Burundi, where conflicts over scarce land and food are at the root of lingering tribal wars and state collapse.
Chance of avoiding five degrees of global warming: negligible if the rise reaches four degrees and releases trapped methane from the sea bed*.
globalwarming.berrens.nl |
