Temperature
The IPCC is predicting a 5C increase in temperature for a doubling of CO2 in the atmosphere. During the industrial revolution, around 1850, CO2 was at 280 parts per million. We are currently at 400 ppm and the doubling would bring us to 560 ppm. We should reach this level in eighty years by human CO2 input alone and without nature adding its contribution. Currently the oceans are absorbing half of our fossil fuel output and forests are still absorbing a good proportion. This will not go on much longer and when the Tundra starts to melt it will release CO2 and Methane in large amounts, the oceans phytoplankton will stop consuming CO2 and the major forest areas will begin to die and stop absorbing CO2. Suddenly the situation will change.
This means that the projection of eighty years for a 5C temperature increase will come much sooner.
From simple observations it would seem that large scale farming will be almost impossible with a 3C increase in temperature and most forests will die and start to burn. There are substantial signs of this all around the World now and we have only increased the temperature by 0.8C.
The IPCC is predicting a 5C increase in temperature for a doubling of CO2 in the atmosphere. During the industrial revolution, around 1850, CO2 was at 280 parts per million. We are currently at 400 ppm and the doubling would bring us to 560 ppm. We should reach this level in eighty years by human CO2 input alone and without nature adding its contribution. Currently the oceans are absorbing half of our fossil fuel output and forests are still absorbing a good proportion. This will not go on much longer and when the Tundra starts to melt it will release CO2 and Methane in large amounts, the oceans phytoplankton will stop consuming CO2 and the major forest areas will begin to die and stop absorbing CO2. Suddenly the situation will change.
This means that the projection of eighty years for a 5C temperature increase will come much sooner.
From simple observations it would seem that large scale farming will be almost impossible with a 3C increase in temperature and most forests will die and start to burn. There are substantial signs of this all around the World now and we have only increased the temperature by 0.8C.
Arctic Sea Ice Melt.
This is potentially the fastest acting result of a warming climate. From reconstructed whaling ship records the Arctic ice minimum was around eleven million square kilometres. When satellite records began in 1979 there were about ten million and now we are down to about four million. With ice volumes falling at the same rate or faster.
This ice loss has upset the balance of the jet streams bringing huge changes to the weather in the northern mid latitudes.
There are detailed explanations on the page dealing with Ice Melt /arctic-sea-ice-weather.html but essentially weather systems get stuck and a rain storm turns into a week or even month long flood. A similar event happens when a dry sunny spell turns into a month long drought.
As this is a recent phenomenon and as it was only vaguely forecast the future is uncertain. However there have been drought and crop loss in China, Russia, Europe and America and the opposite as well with heavy rain and abnormal floods in the same regions.
If the ice extent moves below two million square kilometres, which it could do within five years, then there could be major threat to crops in the most fertile farming areas in the World.
This is potentially the fastest acting result of a warming climate. From reconstructed whaling ship records the Arctic ice minimum was around eleven million square kilometres. When satellite records began in 1979 there were about ten million and now we are down to about four million. With ice volumes falling at the same rate or faster.
This ice loss has upset the balance of the jet streams bringing huge changes to the weather in the northern mid latitudes.
There are detailed explanations on the page dealing with Ice Melt /arctic-sea-ice-weather.html but essentially weather systems get stuck and a rain storm turns into a week or even month long flood. A similar event happens when a dry sunny spell turns into a month long drought.
As this is a recent phenomenon and as it was only vaguely forecast the future is uncertain. However there have been drought and crop loss in China, Russia, Europe and America and the opposite as well with heavy rain and abnormal floods in the same regions.
If the ice extent moves below two million square kilometres, which it could do within five years, then there could be major threat to crops in the most fertile farming areas in the World.
Ocean Acidity.
The changes in the oceans are probably the biggest threat to humanity.
Increasing amounts of CO2 are moving into the oceans and have increased its acidity level by 30%.
Phytoplankton, coral and shell fish can not build their structure and reproduce with high levels of acidity and we have already started to see its affect. The huge mass of phytoplankton consumes CO2 and produces half of the oxygen we breath and the coral reefs support a huge proportion of the Worlds fish. If the systems become unbalanced and these creatures can not reproduce it will upset our lives in ways we can not begin to calculate.
Sea Temperature.
A similar situation arises from increases in sea temperature.The thermohaline circulation distributes heat around the globe and keeps the worlds climate consistent. The sea normaly has a very stable temperature and marine life is not generally equipped to deal with even a small change so a 0.5C increase would bring big changes. Those fish that can are already on the move and changing traditional fishing grounds.
The changes in the oceans are probably the biggest threat to humanity.
Increasing amounts of CO2 are moving into the oceans and have increased its acidity level by 30%.
Phytoplankton, coral and shell fish can not build their structure and reproduce with high levels of acidity and we have already started to see its affect. The huge mass of phytoplankton consumes CO2 and produces half of the oxygen we breath and the coral reefs support a huge proportion of the Worlds fish. If the systems become unbalanced and these creatures can not reproduce it will upset our lives in ways we can not begin to calculate.
Sea Temperature.
A similar situation arises from increases in sea temperature.The thermohaline circulation distributes heat around the globe and keeps the worlds climate consistent. The sea normaly has a very stable temperature and marine life is not generally equipped to deal with even a small change so a 0.5C increase would bring big changes. Those fish that can are already on the move and changing traditional fishing grounds.
Sea level Rise.
The last time the World had 400 ppm of CO2 the sea level was twelve metres higher than today. Many major cities and much of modern humanities infrastructure and farmland is within one metre of sea level. The illustration opposite is set at one meter and shows large areas of the UK farmland and Holland under water. South Florida, the Gulf region and reclaimed Californian farmland up to Sacremento will be major losses but there is a very long list of cities in the same situation. The stability of Greenland and West Antarctica are the key here and many scientists are working on the problem. As yet there is no timetable predicted but we know that sea levels are going to rise and we should see one or two meters before the end of this century.
The last time the World had 400 ppm of CO2 the sea level was twelve metres higher than today. Many major cities and much of modern humanities infrastructure and farmland is within one metre of sea level. The illustration opposite is set at one meter and shows large areas of the UK farmland and Holland under water. South Florida, the Gulf region and reclaimed Californian farmland up to Sacremento will be major losses but there is a very long list of cities in the same situation. The stability of Greenland and West Antarctica are the key here and many scientists are working on the problem. As yet there is no timetable predicted but we know that sea levels are going to rise and we should see one or two meters before the end of this century.
Plants and Wildlife.
The last time the world had today's level of 400 part per million of CO2 was four million years ago and the trees and plants at that time were adapted to the climate that went with it. Those trees had taken thousands or years to evolve to match those condition. The trees we have today are adapted to a CO2 level of 280 PPM and a climate 0.8C cooler than today and are rapidly going into conditions 2C warmer and with dramatically changed rainfall conditions of either drought or flood.
We can expect to see much large numbers of trees and other plant life dying in the coming years.
The last time the world had today's level of 400 part per million of CO2 was four million years ago and the trees and plants at that time were adapted to the climate that went with it. Those trees had taken thousands or years to evolve to match those condition. The trees we have today are adapted to a CO2 level of 280 PPM and a climate 0.8C cooler than today and are rapidly going into conditions 2C warmer and with dramatically changed rainfall conditions of either drought or flood.
We can expect to see much large numbers of trees and other plant life dying in the coming years.