One of the scariest aspects about climate change is all of the unknowns and "possible" scenarios that necessitate using the precautionary principle in a political world where even scientific certainty seems unable to drive significant political change. The newest major international investigations findings that the "tipping points" for all nine scenarios of major geophysical elements of the earth could occur within the next 100 years will hopefully help to shift the current political climate in Canada where delaying action to fight climate change is the favored approach. If ever there was an argument to use precaution, this is it. And the Canadian government should take notice of this newest research because not only the Arctic but the northern Boreal forests are among the tipping points.
The article Scientists identify ‘tipping points' of climate change that appeared in the Independent this week suggests that the cold adapted trees of Siberia and Canada are dying as temperatures rise but the article does not go into details about what the other impacts are of increasing climate change are for the Boreal Forest.
The Boreal Forest, perhaps more than any other ecosystem, is one where annual rhythms are closely attuned to the changing seasons. The Forest, an expansive, belt of conifers, mainly spruces and firs, have adapted to the short days & heavy snowfalls during long northern winters. The compressed summer growing season brings with it, an eruption of insects and migratory birds who flock to the Boreal to breed in this vast forest and participate in a feeding frenzy made possible by the explosion in insect populations. It is partly because this is an ecosystem in climatic transition with extremes of heat and cold that it is more vulnerable to warming than other parts of the Globe.
Jay Malcolm from the faculty of forestry at the University of Toronto completed a study that predicts that 46 percent of natural habitat in Canada will change so dramatically, they will be unable to support the species of wildlife and plants now living in those areas. The challenge with climate change as it is occurring now is the speed at which it is taking place, leaving no time for ecosystems to adapt.
The changes that are taking place are increased drought in the Boreal of the prairie provinces, milder winters leading to low beetle mortality and increased infestations, a warming of the permafrost causing siltation of rivers and lakes, lake erosion, and decreased success of spawning fish. In some regions, wetlands drying up and disappearing and warming is changing the basic chemistry of lakes, making them more susceptible to effects of acid rain. Added to this is an increase in forest fires and more carbon being released; a disastrous recipe!
In the next month, Greenpeace Canada will be releasing a report entitled Turning Up the Heat: Global Warming and the Degradation of Canada's Boreal Forest. This science based report will be a critical resource in understanding the complex dynamics of climate change and the Boreal Forest.
Scientists identify 'tipping points' of climate change
5 February 2008
By Steve Connor, Science Editor
A major international investigation by dozens of leading climate scientists has found that the "tipping points" for all nine scenarios - such as the melting of the Arctic sea ice or the disappearance of the Amazon rainforest - could occur within the next 100 years.
The scientists warn that climate change is likely to result in sudden and dramatic changes to some of the major geophysical elements of the Earth if global average temperatures continue to rise as a result of the predicted increase in emissions of man-made greenhouse gases.
Most and probably all of the nine scenarios are likely to be irreversible on a human timescale once they pass a certain threshold of change, and the widespread effects of the transition to the new state will be felt for generations to come, the scientists said.
"Society may be lulled into a false sense of security by smooth projections of global change. Our synthesis of present knowledge suggests that a variety of tipping elements could reach their critical point within this century under anthropogenic [man-made] climate change," they report in the journal Proceedings of the National Academy of Sciences.
The study came out of a 2005 meeting of 36 leading climate scientists who drew on the expertise of a further 52 specialists. It is believed to be the first time that scientists have attempted to assess the risks of what they have termed "tipping elements" in the Earth's climate system.
The nine elements range from the melting of polar ice sheets to the collapse of the Indian and West African monsoons. The effects of the changes could be equally varied, from a dramatic rise in sea levels that flood coastal regions to widespread crop failures and famine. Some of the tipping points may be close at hand, such as the point at which the disappearance of the summer sea ice in the Arctic becomes inevitable, whereas others, such as the tipping point for the destruction of northern boreal forests, may take several more decades to be reached.
While scenarios such as the collapse of the Indian monsoon could occur within a few years, others, such as the melting of the Greenland ice cap or the West Antarctic ice sheet, may take several centuries to complete. "Our findings suggest that a variety of tipping elements could reach their critical point in this century under human-induced climate change," said Professor Timothy Lenton, of the University of East Anglia, who led the study.
A tipping point is defined as the point where a small increase in temperature or other change in the climate could trigger a disproportionately larger change in the future. Although there are many potential tipping points that could occur this century, it is still possible to avoid them with cuts in greenhouse gases, said Professor Lenton.
He added: "But we should be prepared to adapt ... and to design an early-warning system that alerts us to them in time."
- Arctic sea ice: some scientists believe that the tipping point for the total loss of summer sea ice is imminent.
- Greenland ice sheet: total melting could take 300 years or more but the tipping point that could see irreversible change might occur within 50 years.
- West Antarctic ice sheet: scientists believe it could unexpectedly collapse if it slips into the sea at its warming edges.
- Gulf Stream: few scientists believe it could be switched off completely this century but its collapse is a possibility.
- El Niño: the southern Pacific current may be affected by warmer seas, resulting in far-reaching climate change.
- Indian monsoon: relies on temperature difference between land and sea, which could be tipped off-balance by pollutants that cause localised cooling.
- West African monsoon: in the past it has changed, causing the greening of the Sahara, but in the future it could cause droughts.
- Amazon rainforest: a warmer world and further deforestation may cause a collapse of the rain supporting this ecosystem.
- Boreal forests: cold-adapted trees of Siberia and Canada are dying as temperatures rise