In my last report about climate change I was looking at the plight of polar bears as their frozen habitat shrinks into oblivion. It’s all very sad but it is after all half a world away. I’m still OK, right?
Actually it’s bad news for all of us. I live only a few hundred kilometres from the equator and will be among the hardest hit by this change to the Arctic Ice.
Here’s why.
Scientists say that the pattern of ocean circulation was radically altered in the past when climates were warmer. Ancient warm periods offer insights into future warming. The mid-Pliocene, 3 million years ago, was a period of global warmth that is often considered as an analogue for our future.
During this past warm period, unusually hot surface conditions existed in the northern hemisphere. Models of the Earth’s energy flow point to radically different weather patterns and ocean currents. The loss of the Arctic sea ice will change the Arctic Ocean and the movement of water on a global scale.
Africa, small islands, and Asian mega-deltas are regions that are likely to be badly affected. Rainfall in much of S.E. Asia will be very much less and many areas will become much drier or deserts including Indonesia, Malaysia, and Borneo. It is estimated that a global rise in temperature of only 1.5-2 °C will bring about the catastrophic extinction of 20-30% of the Earth’s species.
This may seem like an inconvenience to some but to people living in agricultural and subsistence economies throughout the tropics this is bad news. The impact of global warming will be disproportionately large for disadvantaged communities where resources, food, and health are already problems (Environmental Justice, Dec. 2009).
A study by the World Health Organization (WHO, 2009) estimated the effect of climate change on human health to date. Climate change was estimated to have been responsible for 3% of diarrhea, 3% of malaria, and 3.8% of dengue fever deaths worldwide in 2004. Total attributable mortality was about 0.2% of all deaths in 2004; of these, 85% were child deaths.
But climate change is only starting. The loss of the Arctic ice cap will catapult the Earth and our society into entirely new situations with new rules. Even a 2 °C rise above the pre-industrial level would be outside the range of temperatures experienced by human civilization.
In the tropical seas coral reefs and their fisheries simply will not survive the temperature rise. Coral bleaching, which kills coral, occurs with rises of as little as 1 °C above the summer maximum. Without corals the food web of reefs will collapse.
Coral reefs occupy only 0.15% of the oceans and yet support about 25% of its species. We know almost nothing about reefs but believe that they have far reaching effects on the whole of the sea.
The collapse of these incredibly complex ecosystems will send not a ripple but a ‘tsunami of change’ through the oceans of the world and through Coral Triangle and Pacific Island communities where some 200 million people are sustained by tropical fisheries.
So what will all these people do when the ice melts?
UNESCO predicts that over 100-150 million people in S.E. Asia alone will be displaced through shoreline erosion, rising sea level, drought, and food shortages by 2050.
Can’t we just increase agricultural output?
By 2007 approximately 40% of the world’s agricultural land was already seriously degraded. If current trends of soil degradation continue as they are in Africa, underdeveloped countries might be able to feed just 25% of their population by 2025 (based on UNU’s Ghana-based Institute for Natural Resources in Africa).
Unprecedented migrations of people due to climate change are likely from rural areas to cities and from developing to more developed countries. It has been argued that environmental degradation in some countries will lead to political and military conflict as resources become scarce (Scott, et al. 2001). Even the simple case of oil reaching $100 a barrel coinciding with drought in 2007 pushed up the prices of grains and meats and caused food riots in 40 countries threatening governments as well as social stability in Africa, Asia, the Middle East, and Latin America and the Caribbean.
As I sit at my computer and look at images of Polar Bears treading across broken pieces of ice I think of what we have done and wonder what will be their future. Am I watching the curtain call for the bears or am I looking at the preview of an environmental apocalypse that I helped create but now am too foolish to stop?
