A deep dive into population data and forecasts of warming imply
that our 6,000-year just-right temperature period could be coming to an end.
A third of humanity may live in
Sahara-like conditions by 2070, unless mass migration occurs.
The exceptionally hot results of the current generation of climate models, which
started delivering worrisome predictions last year, continue to be discussed by climate scientists. (Representational Image) (ISTOCK).
And the year 2020
was all about heat.
A deep dive into population data and forecasts of warming imply
that our 6,000-year just-right temperature period could be coming to an end.
A third of humanity can live in
Sahara-like conditions by 2070, unless mass migration occurs.
It was not expected that lethal combinations of heat and humidity will occur until after midcentury, but a mega-study of 40 years of
hourly weather station data from around the world found that deadly conditions are already flirting with the Persian Gulf and the Indus River Valley.
The same research shows that, since 1979, episodes
of exceptional humidity and heat have doubled in intensity.
On Feb. 6, just days before an iceberg larger than Tampa split
off the continent, Antarctica saw its hottest day on record, hitting 18.4C.
Winter in Europe has been the
warmest it's been measured to date.
The second-hottest summer in Australia triggered the second-worst whitening
of the Great Barrier Reef in 40 years of observation.
And centuries of tree-ring evidence, combined with water-cycle models, show that in 1,200 years, human-driven warming
turned what would simply have been another dry spell into the second-worst drought in the American Southwest.
They're not the End
Of Days, yet.
But in 42 global ecosystems, scientists reviewingenvironmental change data found
that somecould be inching closer to collapse than weanticipated.
To make matters worse, a 30-yearstudy of tropical forests shows that trees
donot minimise our emissions of carbon dioxideas much as they used to.
They consumed athird less CO2 in the last decade than
they didin the 1990s, 21 billion metric tonnes less intotal.
The clouds, meanwhile,
remain a mystery.
Last summer, an unusually cloudless sky over Greenland contributed to the largest drop in the mass of the ice sheet ever recorded,
and yet clouds emerging over the island's northern and western parts helped trap heat that would otherwise have escaped, causing even more melting.
The exceptionally hot results of the new generation of climate models, which
started delivering worrisome predictions last year, continue to be discussed by climate scientists.
One explanation: the way the models
manage clouds might be cooler, skewing outcomes.
And if all that wasn't strange enough, Hawaii's record-breaking 2018 rainfall could have triggered
the Kilauea eruptions that caused two dozen casualties and $800 million in property damage.
It's getting
happier, though.
The amateur American scientist Eunice Foote, who wrote the first known paper on the heat-trapping capacity of CO2 in
1856 and then vanished from posterity, was rediscovered and restored to her proper place in the history of climate.
And over the past 15 years, the ozone hole, which dominated global environmental debates in the 1980s, has shrunk
by around 20 percent, which scientists credit to the historic treaty of 1987 banning the materials that created it.
However, don't take
the success for granted.
In addition to a recent increase in illicit chemicals that kill ozone, scientists
have found that as it ages, the contaminants often leak from pre-1987 infrastructure.
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