Sentences with phrase «clear over a period of several years»

Not exact matches

I have already made it clear elsewhere that the additional resistor effect of human CO2 would be insignificant in relation to that from the rest of the air and the oceans together with the varying solar and oceanic heating and cooling effects but we still need to know for sure whether it is significant at all over periods of less than several hundred years because that may be the time we need to solve our energy, pollution, resource and population problems.

His study, based on carbon - dated tree remains, which were recovered under receding alpine glaciers, gives a clear picture of smaller glacier extent than today in several periods over the past 10,000 years.

If there was any truth to the claims that global warming stopped in the last 10 years, or since 1998, or since 1995, or whatever the latest claim is, then we can see from the earlier 20th Century example that we would already be seeing clear signs of that in declining trends over the last several 30 - year periods.