Global warming speeds up due to Pacific 'flip'

Afterslightly slowing for the past 15 years, global warming is onceagain rising more quickly due to a decade-long weather patternthat warms and cools the Pacific, Britain's meteorological officesaid Monday.

The Met Office said the rate of global warming slowedbetween 1999 and 2014, but has now picked up due to a "flip" inthe Pacific weather pattern.

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"The end of the recent slowdown in global warming is due toa flip in Pacific sea-surface temperatures," said Adam Scaife,head of climate predictions at the Met Office.

Global warming hasnow returned to the level seen in the second half of the 20thcentury.- Adam Scaife, UK Met Office

"This was due to a change in the Pacific Decadal Oscillation, which entered its positive phase, warming the tropics, the westcoast of North America and the globe overall," he said.

World temperatures hit a record high for the third year in arow in 2016, scientists said in January.

Temperatures, lifted mainly by emissions of man-madegreenhouse gases and partly by a natural El Nino weather eventthat released heat from the Pacific Ocean, beat the previousrecord in 2015.

That peak had, in turn, eclipsed 2014.

"After a period during the early 2000s when the rise inglobal mean temperature slowed, the values in 2015 and 2016broke records and passed 1 degree Celsius above pre-industriallevels," said Stephen Belcher, chief scientist at the Met.

"Data from the Met Office shows that global warming hasnow returned to the level seen in the second half of the 20thcentury," he said.

1.5 C target

At a conference in Paris in late 2015, governments agreed aplan to phase out fossil fuels this century and shift torenewable energies such as wind and solar power.

They agreed to limit warming to "well below" 2 degreesCelsius above pre-industrial times, while pursuing efforts for
a 1.5 Celsius limit.

But with global temperatures in 2015 and 2016 already warmed by morethan 1 C, and anuptick in extreme weather underway, the Met said there wasincreasing pressure to meet the 1.5 Celsius threshold.

A study published Monday in Nature Geosciencesuggests that in order to meet the 1.5 C target, global emissions after 2015 must be limited to 240 billion tonnes of carbon. That would require serious emissions reductions, but the good news is that it's a much bigger limit than the IPCC'sestimated limit of 70 billion tonnes.

Among this year's extreme weather events were wildfires thatscorched Europe and North America, floods that submerged SouthAsia and hurricanes that swept through the United States and theCaribbean.

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