Spate of ‘crazy’ weather a wake-up call for mankind

5 August 2011 , Educational Issues

Over the past several weeks and months, various regions of the globe have experienced what can only be described as ‘crazy’ weather. This July, while it was raining quasi-continuously in various parts of Europe, the US was having countless temperature records broken, resulting in a loss of tens of billions of dollars.

And while we lucky, air-conditioned people feel uncomfortable when the temperature climbs a bit higher than usual, Somalia has been going through a severe drought with tragic consequences: 80 per cent of its livestock has perished, the soil has barrenly hardened from the absence of any rain or humidity, and famine has stricken large swaths of the population.

It is true that the past decade was — when temperatures are averaged globally — the hottest in recorded history. And it is also true that we have been witnessing a variety of more intense and more frequent extreme-weather phenomena: the US Oceanic and Atmospheric Administration last month reported that floods, droughts, wildfires, hurricanes and tornadoes had been so severe this past spring that damages had already surpassed $32 billion (Dh117.44 billion).

And the last two winters were likewise bad in both Europe and North America, with rainfall increasing by about 20 per cent.

Researchers tell us that if this trend continues, within decades, if not years, we will be routinely witnessing the record snowstorms that people experienced last winter in the northern regions of the globe as well as a significant increase in the number of heat waves like those that millions of people have just lived through.

So more and more often, I get asked whether the crazy days we are experiencing due to global warming? It does indeed seem like the weather is getting worse. Or is it? Well, one must look at the situation carefully, for it turns out that the early years of the 20th century had seen similar weather patterns — when ‘climate change’ had not yet become a common idea.

Am I saying that the variety of extreme weather phenomena that are occurring nowadays cannot be related to global warming? No, I am saying there is a relation, but it is not so straight-forward.

Most climatologists agree that the increase in greenhouse gases in the atmosphere is at least a contributing cause for the extreme weather outbreaks that have become more frequent lately. Why is that? Simply put, greenhouse gases raise the air’s temperature, hence more heat waves, droughts, and wildfires; moreover, a warmer atmosphere can retain more water vapour, thus leading to more sudden rainfall and floods.

But the problem is much more complex because the weather is always highly variable, and warming (of whatever cause) does not always produce the extreme phenomena mentioned above. In fact, one must be careful not to relate weather, which is mostly local and temporary, to climate, which is regional and longer-termed.

That is why it is often preferable to speak about ‘climate change’ instead of ‘global warming’; the latter idea is correct on average but does not give a good picture of what is happening in specific areas of the planet.

Now, a number of commentators have seized upon changes occurring in the Sun’s activity and attempted to relate them to Earth’s recent and future climate changes. In that case, their reasoning goes, the Sun would be the culprit for any observed changes, not the human-produced greenhouse gases.

Indeed, the Sun goes through a cycle of surface activity (sunspots, flares, and prominences), and it is now on the ascending part of its cycle, so it is tempting to infer that our environment gets affected by it. And tree rings do show variations during times when the Sun is very active or very quiet. But to what extent does the Sun, and its cycle of activity, affect the climate? The short answer is: not much; the longer, more detailed answer I will present some other time.

So to make a long story short (or to simplify a complex problem): first, extreme weather phenomena have indeed gotten more frequent and intense in various parts of the world, and though it can easily be argued that they must at least partially be related to the warming of the atmosphere, other factors (e.g. ocean streams) are also at play, and one must be careful not to confuse climate trends and weather effects.

Secondly, the Sun’s activity and its cycle can be considered a factor when considering the Earth’s climate, but only a secondary one at best. So while we can’t blame this or that effect specifically for the extreme weather we witness here or there, it is still a good policy to individually and collectively cut down on greenhouse gas production.