why there's no sign of a climate conspiracy in hacked emails

NewScientist | The leaking of emails and other documents from the Climate Research Unit (CRU) at the University of East Anglia, UK, has led to a media and political storm. The affair is being portrayed as a scandal that undermines the science behind climate change. It is no such thing, and here's why.

We can be 100 per cent sure the world is getting warmer

Forget about the temperature records compiled by researchers such as those whose emails were hacked. Next spring, go out into your garden or the nearby countryside and note when the leaves unfold, when flowers bloom, when migrating birds arrive and so on. Compare your findings with historical records, where available, and you'll probably find spring is coming days, even weeks earlier than a few decades ago.

You can't fake spring coming earlier, or trees growing higher up on mountains, or glaciers retreating for kilometres up valleys, or shrinking ice cover in the Arctic, or birds changing their migration times, or permafrost melting in Alaska, or the tropics expanding, or ice shelves on the Antarctic peninsula breaking up, or peak river flow occurring earlier in summer because of earlier snowmelt, or sea level rising faster and faster, or any of the thousands of similar examples.

None of these observations by themselves prove the world is warming; they could simply be regional effects, for instance. But put all the data from around the world together, and you have overwhelming evidence of a long-term warming trend.