Typhoon Haima is expected to reach category 5 strength by Wednesday. Photo: The Weather Channel Haitians, hard hit by Hurricane Matthew, await aid from a US helicopter earlier this month. Photo: Rebecca Blackwell
As the Philippines braces for its second major typhoon in just five days, a Canadian glacier spawns a giant iceberg and eastern Australia mops up from a record wet spell, climate scientists can pick from a world of weird weather to highlight evidence of global warming under way.
Just days after nations agreed to curb production of greenhouse gases 10,000 times more potent than carbon dioxide and a fortnight before the Paris climate agreement comes into force on November 4, many regions are experiencing bizarre conditions.
September continued the run of exceptional global warmth, with last month narrowly edging last year as the hottest September on record, NASA, the US space agency, said overnight.
After data adjustments, NASA said 11 of the past 12 months had set monthly high-temperature records. (See chart below). This year is on course to smash previous records for annual heat set in 2015 and in the year before that.
Climate scientists, such as NASA’s Gavin Schmidt, emphasise that while individual weather events and even monthly rankings may be newsworthy, “they are not nearly as important as long-term trends”.
Here, though, there are many worrying pointers.
The Philippines is facing the potential for a category 5-strength typhoon Haima just days after typhoon Sarika blew through, leaving a trial of death and destruction that has now extended to neighbours Vietnam and China.
Recent research indicates the western Pacific is experiencing stronger cyclones with the frequency increasing as much as four-fold. Porcupine spike
In Canada, the Porcupine Glacier in British Columbia retreated more than two kilometres “in one leap”, when a major iceberg broke off during the summer, The Globe and Mail reported recently. (See their chart below:)
Mauri Pelto, professor of environmental science at Nichols College in Massachusetts, said he couldn’t identify a bigger iceberg carved from a Canadian glacier in a quarter century of work.
“It’s just a highlight example of what’s happening [from climate change],” Dr. Pelto was quoted as saying. “I have worked on over 200 glaciers just in that area, and all but one have been retreating.”
The behaviour of ice of a different kind caught the attention of Andy Pitman, director of the ARC Excellence for Climate System Science at the University of NSW.
After rivalling previously lows in 2007 and 2012, this year’s recovery of Arctic sea ice as winter approaches has slowed sharply, placing it again at record low levels. (See chart below, supplied via Zack Labe, from the University of California, Irvine.)
With less sea ice, more of the sun’s energy is absorbed by the Arctic seas rather than reflected back to space, accelerating the pace of warming in an area that’s warming faster than almost anywhere else.
“It’s moving outside it’s normal operating range,” Professor Pitman said of the sea ice trend. “Climate extremes are emerging much faster than climate scientists thought.” Rain extremes
While major weather events can’t all be attributed to climate change rather than natural variability, a warming world makes them more likely.
Scientists, for instance, estimate that the atmosphere can hold 7 per cent more moisture for each degree of warming – and we’ve had at least that since the Industrial Revolution triggered a rapid increase in greenhouse gases from the burning of fossil fuels and land-clearing for agriculture.
Hurricane Matthew, which scrapped along the east coast of the US earlier this month, is estimated to have dumped as much 52 trillion litres on the US, triggering widespread flooding, according to Ryan Maue, a US-based meteorologist.
Typhoon Sarika, which left at least 25 dead in the Philippines last week, is now expected to bring flooding rains to south-east China.
Behind Sarika, though, looms a more powerful storm, super typhoon Haima, which is likely to generate peak gusts of more than 300 km/h by Wednesday as it nears the northern Philippine island of Luzon.
“[A]long with the dangers of storm surge flooding and damaging winds, rainfall flooding and landslides would also be major threats in Luzon, given saturated ground from Sarika,” the weather杭州m website said in a report. “More than a foot of rain could fall over northern portions of Luzon as Haima moves through.”
Much of eastern Australia has copped its drenching in recent weeks, although the rains have fortunately been more spread out.
As the Bureau of Meteorology said in a special climate statement last week, the Murray Darling Basin had its wettest September on record, continuing a string of wet months.
“The May to September period was Australia’s wettest on record, with each of the five individual months ranking in the 10 wettest in the last 117 years,” the report said. ‘Off the charts’
“You’re seeing more extreme events and in most of the parts of climate that affect people,” Professor Pitman said.
Heatwaves, for instance, that used to last typically three days, might be stretching in some places out to 10 days.
“It’s like Usain Bolt doing a 4-second,100-metre run,” he said. “It’s completely off the charts.”
Professor Pitman’s centre will shift more of its focus to the study of climate extremes after securing funds from the Australian Research Council last month.
“There is some emerging evidence that the system is redefining itself,” Professor Pitman said.
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