Monday, April 30, 2007

Climate Catastrophes In The Solar System

A quick look by Science Daily at how our two nearest planetary neighbours, Venus and Mars, have both had something of a difficult climatic past, although before the problems started, it is possible that both planets bore some resemblance to Earth, in that they may once have had biospheres of their own.

David Grinspoon, involved with the Venus Express mission, is among those who believe that by studying the climate history of these two planets, we may be able to gain an insight into the future of our own.

The key weapon in a climate scientist’s arsenal is the climate model, a computer programme that uses the equations of physics to investigate the way in which Earth’s atmosphere works. The programme helps predict how the atmosphere might change in the future. “To members of the public it must seem like climate models are crystal balls, but they are actually just complex equations” says David Grinspoon, Denver Museum of Nature and Science, and one of Venus Express’s interdisciplinary scientists.

Actually I don't think the average lay-person does have a perception of scientists using crystal balls to predict the future, and there would be much despondency and lowering of public morale if this was thought to be the case.

The problem here is to inform the public as accurately as possible, without giving us too much incomprehensible data that renders the research opaque, while still giving enough relevant detail for us to be able to have a clear idea of some of the dangers facing us, and what actions, if any, we can take on a societal or individual basis that will forestall some of the effects. Back to Venus...

They believe that the planet experienced a runaway greenhouse effect as the Sun gradually heated up. Astronomers believe that the young Sun was dimmer than the present-day Sun by 30 percent. Over the last 4 thousand million years, it has gradually brightened. During this increase, Venus’s surface water evaporated and entered the atmosphere. “Water vapour is a powerful greenhouse gas and it caused the planet to heat-up even more. This is turn caused more water to evaporate and led to a powerful positive feedback response known as the runaway greenhouse effect,” says Grinspoon.

It is thought that as we pollute our own planet to the extent that dangerous greenhouse gases are created in great quantity, the fate of the Earth will be to become Venus 2.0 - although of course, other factors than humans may be involved in the case of Earth, it would appear that humans have played a large part in our potential downfall. Next, we're off to 'frigid' Mars...

Understanding Mars’ past is equally important. ESA’s Mars Express is currently investigating the fate of the Red Planet. Smaller than the Earth, Mars is thought to have lost its atmosphere to space. When Martian volcanoes became extinct, so did the planet’s means of replenishing its atmosphere turning it into an almost-airless desert.

“What happened on these two worlds is very different but either would be equally disastrous for Earth. We are banking on our ability to accurately predict Earth’s future climate,” says Grinspoon. Anything that can shed light on our own future is valuable. That is why the study of our neighbouring worlds is vital

However, just studying other planets may only help us understand what is going wrong here, and there is no way at the moment that we can prevent climate change from happening, especially given some of the wild and sudden temperature swings that have happened here, in times before humans were around in sufficient number to cause climatic change.

see also: Earth's Climate Is Seesawing, According To Climate Researchers

and: Ocean's 'Twilight Zone' Plays Important Role In Climate Change

and: Climate Change Hits Mars

and: Climate Change Controversies: A Simple Guide

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