Why we shouldn’t confuse climate and weather

We have always been baffled by the weather and have often used strange arguments to explain its unexpected behaviour. More than 2,000 years ago, one hapless Roman citizen was so worried that unusual gales and storms might be due to the impiety of the nation that he asked the gods for guidance via a carved lead tablet which he left at a local oracle.

Today we have a better idea of the factors that influence our weather, though we still struggle to make sense of the reams of data – wind, pressure, sunshine, temperature, moisture levels, and other factors – that we now know influence the daily regimes of rain and sun that we experience.

Most of these factors are short-term phenomena; others are longer-term influences. The former determine our weather, while the latter affect our climate. And that is the essential difference between weather and climate. It is all a matter of time. Weather is determined by conditions of the atmosphere over a short period and climate is determined by the way the atmosphere behaves over relatively long periods of time. Weather can change quickly; climate alters very slowly.

However, the rules are changing. We have begun to alter the makeup of our atmosphere by pumping out greenhouse gases from our factories, cars and power stations and this, in turn, is changing our climate, causing air and sea temperatures to rise inexorably. This is global warming, a phenomenon now accepted as reality by the vast majority of the world’s meteorologists and climate experts.

Indeed, it was their warnings that led to the recent Paris accord on climate changewhich is intended to channel a route for nations to agree cuts in fossil fuel use and so reduce greenhouse gas emissions. Scientists know changes lie ahead but find that predicting exactly how our weather will change as long-term climate alters it is complex and vexing. Yes, it is very likely that there will be more intense hurricanes and storms in a warming world but determining whether an individual event – however damaging – is the result of climate change or not is almost impossible given the plethora of other short-term factors that could also influence the triggering of such a storm.

Determining how climate change is progressing is also difficult because long-term data sets are required to build up an accurate assessment. These can take three decades to assemble. Hence the reluctance of scientists to give cast-iron assurances about exactly how much our climate is altering. As the years pass, however, the more certain they get.

Source: the guardian

Posted by admin on Dec 20 2015. Filed under News at Now, Uncategorized. You can follow any responses to this entry through the RSS 2.0. You can leave a response or trackback to this entry