THE AUTHOR
Mark Lynas is the author of Six Degrees and several other environmental books, including High Tide, and The God Species. He speaks on climate change, biotechnology and nuclear power. The Maldives Islands employed him as a climate change advisor. Six Degrees became a National Geographic program – narrated by Alec Baldwin – and has been watched by millions around the world. Mr. Lynas became a Visiting Fellow in 2013 at Cornell University. His responsibilities include teaching environmental courses, and advising on biotechnology in developing countries by providing environmental support and lessons in food security improvements.
INTRODUCTION
Author Mark Lynas presents a degree by degree look of what to expect from a warming world. His book brings together what environmental scientists portend about the consequences of human pollution for the next hundred years. An increase of 1o Celsius would distroy most of the coral reefs and melt many of the mountain glaciers. Ecosystems in the Brazilian rainforest would collapse at a 3o rise. Greenland’s ice cape would melt, and new deserts would form across the US and Africa. A 6o increase would kill most of the life on Earth.
Of course, the implications depend on where you live. Land mass warming is more intense than the ocean, and it is exaggerated over the Arctic, where retreating sea ice reflects less light and so produces less cooling, according to Kevin Trenberth (Trenberth et al. 2003). He is a senior scientist at the National Center for Atmospheric Research. Each degree increase in global temperature could mean up to 10% less rainfall around the world.
While the warmer oceans may not produce more storms and hurricanes, they will be more intense. The combination of differing patterns of precipitation and earlier snowmelt will increase the risk of wildfires, according to Trenberth (Trenberth et al. 2003). The day-to-day weather may remain about the same, but extreme events will become more extreme. With less stream flow in some river basins there will be a reduction in food crops in the U.S., Africa and in India. And the impacts the author predicts only increase in severity as the temperature rises above 2o.
A 3o increase within the next century is likely, resulting in the disappearance of many coastal cities and an increase in worldwide water stress. The changes will be even greater for 4o. In fact, the additional warming could have dramatic consequences, such as the complete collapse of farming in sub-Saharan Africa.
A DEGREE BY DEGREE DESCRIPTION
Even if greenhouse gas emissions were stopped immediately the current concentrations would still mean a global rise of between 0.50 and 10C. While a shift of a 1o is barely felt by human skin, an average increase of 1o across the planet would mean a big change in climatic conditions.
It has been calculated that a 1o increase would eliminate fresh water from a third of the world’s land surface. While the tropical lands are nearing the brink, the Arctic already may have passed the point of no return. Warming near the pole is much faster than the global average. The Arctic icecaps and glaciers have lost over 400 km3 of ice in the last few decades. The permafrost is dissolving, destabilizing large areas as the ground collapses beneath buildings, roads and pipelines. Polar bears and Inuits are being forced off the arctic ice sheets. This means more heat being absorbed by the air and ground producing a positive feedback effect.
Changes in the ocean are even faster. The ice caps reflect more than 80% of the sun radiant heat but the bare ocean absorbs almost 95% of the solar radiation. As the more ice melts more ocean is exposed, absorbing solar heat, raising temperatures and increasing the cycle. Low-lying countries like the Maldives will be submerged as sea levels rise. And the coastal areas in the US, and the Caribbean will be hit by ever stronger hurricanes as the temperature of the water increases.
It will be interesting to see how people behave once our urban areas begin to change. How will society change when people become desperate?
2o OF WARMING
At this level, the world’s summers will be hotter than normal with more people dying of heat stress. Across Europe, the increased temperature will cause between 20,000 and 40,000 deaths annually. Farmers will lose billions of dollars of crops. Agriculture will be devastated. Forest-fire damage will cost many countries billions too. The decreased flows of most rivers will not provide enough water for irrigation and hydroelectricity.
In the 2o world, the movement of people is likely to reverse, switching to a mass movement of people moving away from the coast.
Greenland will warm much faster than the rest of the world. It will begin to tip into irreversible melt once global temperatures rise past a mere 1.2C, but scientist predict that the “tipping point” for Greenland won’t arrive until average temperatures have risen by 2.7C. At this rate its ice sheet would completely vanish in less than 140 years. Cities like Miami, Manhattan and Central London would be underwater. Half the world’s population would have to move to higher ground.
As glaciers disappear, so people will lose their water supplies. Their runoff will not supply the rivers that deliver freshwater to hundreds of millions. Water shortages and famine will follow in large areas. Ecosystems will unravel as species either migrate or fall out of synch with each other.
By the time global temperatures warm by 2o more than a third of living species will face extinction.
3o OF WARMING
More CO2 will accumulate in the atmosphere because a warming ocean will absorb less, making matters worse. As the soil warms, bacteria will accelerate the breakdown of its stored carbon, releasing it into the atmosphere. A global increase of 3o will throw the carbon cycle into reverse. So much carbon will be released into the atmosphere that it could tip the planet into runaway global warming by the middle of this century.
These higher temperatures result in greater evaporation, which cause further drying out vegetation and soils. As the mountains lose their snow, the cities and farms will lose more of their water. Dried-out forests and grasslands will perish to forest and range fires.
Given the choice between starving in place and moving, people move. For example, by the latter part of this century millions of Pakistani citizens may be facing this choice. Pakistan may find itself joining the growing list of failed states, as the government collapses and armed gangs seize what food is left.
Everywhere, hungry and thirsty people will be on the move, from Central America into Mexico and the US, and from Africa into Europe.
4o OF WARMING
The streams of refugees will include those fleeing from coasts to safer interiors. The world’s economies will be devastated. China will be on a collision course with the rest of the world. China will soon be consuming at the same rate as Americans. They will need two-thirds of the world’s food harvest and burn 100m barrels of oil a day. That spells catastrophe. But it’s worse than that: “By the latter part of the 21st century, if global temperatures are more than 3o 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 (Lynas 2008). For people throughout much of the world, starvation will be a regular threat; but it will not be the only one.
Air-conditioning will be mandatory for anyone wanting to stay cool, putting more stress on our energy systems, all the while putting more greenhouse gases into the air.
Now one of the most dangerous situations will begin – the runaway thaw of the permafrost. Scientists believe that 500 billion tonnes of carbon will be released from the Arctic region. And how much will that add to global warming. One degree? Two? Three? As with the Amazon collapse and the carbon-cycle feedback in the 3o increase, the 4o devastation will be unstoppable.
5o OF WARMING
At this temperature increase the world is completely different. The polar ice sheets have disappeared, the rainforests have burnt up and turned into deserts and the ALPS are dry and lifeless. The rising oceans have moved deep into the continental interiors. There has been a population shift to the thawed regions of the north. But even here the summers may be too hot for crops to grow and there is no guarantee that these governments will admit southern refugees.
Globalism in the 5o world will break down, customers will have nothing to buy because producers will have nothing to sell. There will be no international aid. Where no refuge is available, civil war and societal collapse seems likely. 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.
6o OF WARMING
The possibility of warming on this scale lies within the 21st-century. To see comparable climatic conditions, we have to go back to the Cretaceous period, which ended with mass extinction. Or at the end of the Permian period, about 250m years ago, when temperatures rose by 6o, and 95% of species were wiped out.
On land, the winners will be the fungi that flourish on dying vegetation. However, a warmer ocean is a killer. With less dissolved oxygen conditions become stagnant and anoxic, killing all the higher forms of life from plankton to whales. With increased melt and warm water expansion the sea levels rise by 20 meters. Super-hurricanes will hit the coastal areas triggering flash floods that no one could survived.
As if this isn’t enough, what happens when warming water releases the stored methane from the sea bed? Methane is up to 80 times worse than CO2 as a greenhouse gas. And unlike CO2, its flammable. It has been estimated that a large methane eruption could release the energy equivalent to 100,000 times more than the world’s entire stockpile of nuclear weapons. Lynas stated, “It is not too difficult to imagine the ultimate nightmare, with oceanic methane eruptions near large population centres wiping out billions of people – perhaps in days.” Then comes the “rotten egg” smell of the released hydrogen sulphide from the stagnant oceans.
WE”RE DOOMED OR ARE WE?
- Lynas, M. 2008. Six degrees: Our future on a hotter planet. National Geographic, Washington, D.C.
- Trenberth, K. E., A. Dai, R. M. Rasmussen, and D. B. Parsons. 2003. The Changing Character of Precipitation. Bulletin of the American Meteorological Society 84:1205-1217.