Wednesday, 11 August 2004 - 10:35 AM EDT
1.Dr.Wigley believe that "climate models are basically weather models that concentrate on different time scales. The standard difference between weather and climate is that climate is, in simple terms, the average weather. So climate is what we can expect to happen for a particular season or a particular year, but it's not going to tell us what's going to happen day by day."
2.He believe that climate change "will be longer than a season, really. Just to give you an example, one of the concerns about future climate change, particularly in Europe, is changes in storminess. That doesn't mean we're going to be [able] to say, you know, there will definitely be more storms, they will be more intense, and they'll happen this time of the year, or they'll last for this certain period of time. But what we can say is that there may be, on average, more storms."
3."So if we looked at the average weather situation in the winter over a period of ten years, there would be more storms. That doesn't mean there are going to be more storms in any individual year. It means that the long-term prediction, the average prediction over a decade or more, is that there would be more storms. I'm not saying actually that there will be more storms, but that happens to be an area where there's a considerable amount of uncertainty. But that's just an example of the difference between weather and climate.
If that variability were very large, then we would need a very big human-induced change in order to identify the effect of human activities. If that variability was zero, then any small change would be easily identifiable. So, really, it's the background variability or noise that is the concern. And this is, in technical jargon, referred to as a signal-to-noise problem. We need to know what the signal is, what the changes wrought by human activities might be--and we use complicated climate models to do that--but we also need to know what the noise is against which this signal is appearing."
4."There are all sorts of problems with different instrumentation, different methods of measuring temperature, different ways of exposing thermometers. The meteorological instrumentation exposure used in the nineteenth century was very different from what is used today and another problem associated with temperature measurements, and that is urbanization. As cities have grown, so their own activity causes a so-called urban heat island, so temperatures in an urban area would be expected to increase with time, simply because of this urban heat island effect."
5.I can't explain my own research and of course I do not agree or disagree with Dr.Wigley. I'll be specific and honest. Many articles which we passed away very difficult for me. As you now, this is my first steps and now I look like a baby who only begin read. That's why I don't understand many words, but I study every day and try to learn.
6."We don't necessarily believe that all global warming is bad, by the way. We don't necessarily believe that the increase in carbon dioxide is uniformly bad, because carbon dioxide accelerates plant growth and can be good, potentially, for agriculture. But what we're afraid of is that if the planet warms too much, we're going into unknown territory. We can't predict the climate well enough to know what to expect. So we certainly don't want to go too far down the road, down the pathway of global warming. We have time to think about what to do. But eventually, we have to do something dramatic.
We really have to move completely away from using fossil fuels for energy."