Climate Change 2001:
Working Group I: The Scientific Basis
Other reports in this collection

2.8 Are the Observed Trends Internally Consistent?


Figure 2.39a: Schematic of observed variations of various temperature indicators.

Figure 2.39b:
Schematic of observed variations of various hydrological and storm-related indicators.

It is very important to compare trends in the various indicators to see if a physically consistent picture emerges, as this will critically affect the final assessment of our confidence in any such changes. A number of qualitative consistencies among the various indicators of climate change have increased our confidence in our analyses of the historical climate record: Figure 2.39a and b summarises the changes in various temperature and hydrological indicators, respectively, and provides a measure of confidence about each change. Of particular relevance are the changes identified below:

We conclude that the variations and trends of the examined indicators consistently and very strongly support an increasing global surface temperature over at least the last century, although substantial shorter-term global and regional deviations from this warming trend are very likely to have occurred.



Other reports in this collection