Environment

Climate Change & Equity

What does climate change portend for the planet? And for the citizens of Asia and Africa?

BBC World’s Horizon program today aired an episode on a phenomena called Global Dimming. Put simply, the amount of sunlight reaching the earth’s surface has declined by between 5-25% over the past 50 years. This is an empirical fact, proven by independent studies in Australia, Israel, Russia, and Europe. Caused by visible particulate pollution , the dimming has a cooling effect on the earth.

Now, the fact that pollution would cause a cooling effect has been known before. But the extent of the dimming effect and its knock-on effects only became clear to me today - with disturbing implications.

First, global dimming has had a cooling, and therefore, regressive effect on global warming caused by greenhouse gases. Would our planet not be much warmer without the particulate pollution, but still with the CO2? Recent evidence suggests that the true impact of global warming may well have been underestimated, not accounting for the increased sunlight in the absence of global dimming.

By itself, this suggestion is worrisome enough, because even as we have continued to burn more fossil fuels, we have managed to burn them cleaner. Legislation and technology have aggressively reduced particulate emissions over the past 50 years, and Europe and America are breathing visibly cleaner air. Are we, then, reaching a point where Global Dimming may stop protecting us from Global Warming. And what if that happens?

For 3 days after September 11, all commercial flights in the United States were grounded. This was a rare, indeed unique, opportunity to study the climate in the USA in the absence of contrails - condensation or vapour trails - from commercial jet aircraft. While individual contrails are small, the accumulation of such contrails in areas of high airline traffic can cover significant parts of the sky. A study following 9/11 showed the temperature range between day and night temperatures was 1 degree C higher during those 3 days. Multiple explainations are possible, but it does fit the Global Dimming paradigm.

The second implication, which has received scant attention in most debates, is how climate change affects different regions. Horizon suggested that dimming may have been behind the Sahel droughts in the 1970s and 80s (that killed over a million and affected over 50 million), by cooling the Atlantic due to pollution in Europe.

Clearly, it is unwise to jump too quickly to that conclusion. Yet, it is widely accepted that climate change in general will have regional and global implications, beyond the source of pollution. This was evident in an experiment conducted in the Maldives, where Global Dimming was stronger in the northern islands, which received polluted air coming from India, as opposed to the southern islands which received cool, clean air from the Antarctic.

In the west, where much of the climate change debate occurs, it is viewed more as a process to be managed and reversed. Seen primarily as a public bad, Europe’s concept of fairness and equality emphasize that all countries must participate equally to reduce emissions, in negotiations such as Kyoto. Yet, the reality in the South is very different.

There, climate change is not a process. It is a question of the survival of a people who have no or little control over the process itself. It threatens their very existence, while providing no recourse to prevention.

Consider this. The deadliest hurricane to hit the USA in the past 100 years was in 1900. It killed over 8000 people. Hurricane Katrina, a more recent example, left tens of thousands homeless, but a mere 236 people dead. The damage, while widespread, was primarily economic.

Bangladesh is the most storm-prone country in the world. In 1970, the Bhola cyclone - the worst recorded storm to date - killed about 500,000 people. In 1991, another cyclone killed 140,000 people.

Consider this. Current predictions say that global warming would result in a 5 degree increase over the next 100 years. However, if one takes out the cooling effect of global dimming, then Horizon indicates temperatures could rise by up to 10 degrees. If that happens, Europe and much of North America will become very uncomfortable.

Much of Africa and India, however, will be uninhabitable.

Where is the equity in that?

© 2006 The Discomfort Zone.