The supposed 'consensus¹' on man-made global warming is facing an inconvenient² challenge after the release of new temperature data showing the planet has not warmed for the past 15 years.

新的温度数据显示，地球在过去的15年间并无变暖。这一数据发布后，人为引起全球变暖的“共识”受到了不利挑战。

The figures suggest that we could even be heading for a mini ice age to rival the 70-year temperature drop that saw frost fairs held on the Thames in the 17th Century.

Based on readings from more than 30,000 measuring stations, the data was issued last week without fanfare³（吹牛，炫耀） by the Met Office and the University of East Anglia Climatic Research Unit. It confirms that the rising trend in world temperatures ended in 1997.

Meanwhile, leading climate scientists yesterday told The Mail on Sunday that, after emitting unusually high levels of energy throughout the 20th Century, the sun is now heading towards a 'grand minimum' in its output, threatening cold summers, bitter winters and a shortening of the season available for growing food.

Solar output goes through 11-year cycles, with high numbers of sunspots seen at their peak.

We are now at what should be the peak of what scientists call 'Cycle 24' – which is why last week's solar storm resulted in sightings of the aurora⁴（极光，曙光） borealis further south than usual. But sunspot numbers are running at less than half those seen during cycle peaks in the 20th Century.

Analysis by experts at NASA and the University of Arizona – derived⁵ from magnetic-field measurements 120,000 miles beneath the sun’s surface – suggest that Cycle 25, whose peak is due in 2022, will be a great deal weaker still.

According to a paper issued last week by the Met Office, there is a 92 percent chance that both Cycle 25 and those taking place in the following decades will be as weak as, or weaker than, the 'Dalton minimum' of 1790 to 1830. In this period, named after the meteorologist John Dalton, average temperatures in parts of Europe fell by 2C.

However, it is also possible that the new solar energy slump⁶ could be as deep as the 'Maunder minimum' (after astronomer⁷ Edward Maunder), between 1645 and 1715 in the coldest part of the 'Little Ice Age' when, as well as the Thames frost fairs, the canals of Holland froze solid.