The world has been getting hotter for decades but a sudden and extraordinary surge in heat has sent the climate deeper into uncharted territory — and scientists are still trying to figure out why.
Over the past two years, temperature records have been repeatedly shattered by a streak so persistent and puzzling it has tested the best-available scientific predictions about how the climate functions.
Scientists are unanimous that burning fossil fuels has largely driven long-term global warming, and that natural climate variability can also influence temperatures one year to the next. But they are still debating what might have contributed to this particularly exceptional heat surge.
Photo: EPA-EFE
Experts think changes in cloud patterns, airborne pollution and Earth’s ability to store carbon could be factors, but it would take another year or two for a clearer picture to emerge.
“Warming in 2023 was head-and-shoulders above any other year, and 2024 will be as well,” Gavin Schmidt, director of the NASA Goddard Institute for Space Studies said last month.
“I wish I knew why, but I don’t,” he added. “We’re still in the process of assessing what happened and if we are seeing a shift in how the climate system operates.”
‘UNCHARTED TERRITORY’
When burned, fossil fuels emit greenhouse gases like carbon dioxide that trap heat near the Earth’s surface.
As fossil fuel emissions have risen to record highs last year, average sea surface and air temperatures have curved upwards in a consistent, decades-long warming trend.
But in an unprecedented streak between June last year and September this year, global temperatures were unlike anything seen before, said the World Meteorological Organization — and sometimes by a considerable margin.
The heat was so extreme it was enough to make last year — and then this year — the hottest years in history.
“The record global warmth of the past two years has sent the planet well into uncharted territory,” said Richard Allan, a climate scientist from the UK’s University of Reading.
What occurred was “at the limit of what we would expect based on existing climate models,” said Sonia Seneviratne, a climatologist from ETH Zurich in Switzerland.
“But the overall long-term warming tendency is not unexpected” given the amount of fossil fuels being burned, she added.
’DIFFICULT TO EXPLAIN’
Scientists said that climate variability could go some way to explaining what happened.
Last year was preceded by a rare, three-year La Nina phenomenon that had a strong cooling effect on the planet by pushing excess heat into the deep oceans.
This energy was released back to the surface when an opposite, warming El Nino event took over in the middle of the year, boosting global temperatures.
But the heat has lingered even after El Nino peaked in January.
Temperatures have not fallen as fast as they rose, and last month was still the second-warmest on record.
“It is difficult to explain this at the moment,” said Robert Vautard, a member of the UN’s climate expert panel IPCC. “We lack a bit of perspective. If temperatures do not drop more sharply in 2025, we will really have to ask ourselves questions about the cause,” he said.
JURY OUT
Scientists are looking for clues elsewhere.
One theory is that a global shift to cleaner shipping fuels in 2020 accelerated warming by reducing sulphur emissions that make clouds more mirror-like and reflective of sunlight.
Another peer-reviewed paper this month looked at whether a reduction in low-lying clouds had let more heat reach Earth’s surface.
At the American Geophysical Union conference this month, Schmidt convened scientists to explore these theories and others, including whether solar cycles or volcanic activity offered any hints.
There are concerns that without a more complete picture, scientists could be missing even more profound and transformational shifts in the climate.
“We cannot exclude that some other factors also further amplified the temperatures... the verdict is still out,” said Seneviratne.
Scientists this year warned that Earth’s carbon sinks — such as the forests and oceans that suck CO2 from the atmosphere — had suffered an “unprecedented weakening” last year. This month, the US National Oceanic and Atmospheric Administration said the Arctic tundra, after locking away C02 for millennia, was becoming a net source of emissions.
Oceans, which have acted as a massive carbon sink and climate regulator, were warming at a rate scientists “cannot fully explain,” said Johan Rockstrom of the Potsdam Institute for Climate Impact Research.
“Could this be a first sign of a planet starting to show a loss of resilience? We cannot exclude it,” he said last month.
If one asks Taiwanese why house prices are so high or why the nation is so built up or why certain policies cannot be carried out, one common answer is that “Taiwan is too small.” This is actually true, though not in the way people think. The National Property Administration (NPA), responsible for tracking and managing the government’s real estate assets, maintains statistics on how much land the government owns. As of the end of last year, land for official use constituted 293,655 hectares, for public use 1,732,513 hectares, for non-public use 216,972 hectares and for state enterprises 34 hectares, yielding
The small platform at Duoliang Train Station in Taitung County’s Taimali Township (太麻里) served villagers from 1992 to 2006, but was eventually shut down due to lack of use. Just 10 years later, the abandoned train station had become widely known as the most beautiful station in Taiwan, and visitors were so frequent that the village had to start restricting traffic. Nowadays, Duoliang Village (多良) is known as a bit of a tourist trap, with a mandatory, albeit modest, admission fee of NT$10 giving access to a crowded lane of vendors with a mediocre view of the ocean and the trains
Traditionally, indigenous people in Taiwan’s mountains practice swidden cultivation, or “slash and burn” agriculture, a practice common in human history. According to a 2016 research article in the International Journal of Environmental Sustainability, among the Atayal people, this began with a search for suitable forested slopeland. The trees are burnt for fertilizer and the land cleared of stones. The stones and wood are then piled up to make fences, while both dead and standing trees are retained on the plot. The fences are used to grow climbing crops like squash and beans. The plot itself supports farming for three years.
President William Lai (賴清德) on Nov. 25 last year announced in a Washington Post op-ed that “my government will introduce a historic US$40 billion supplementary defense budget, an investment that underscores our commitment to defending Taiwan’s democracy.” Lai promised “significant new arms acquisitions from the United States” and to “invest in cutting-edge technologies and expand Taiwan’s defense industrial base,” to “bolster deterrence by inserting greater costs and uncertainties into Beijing’s decision-making on the use of force.” Announcing it in the Washington Post was a strategic gamble, both geopolitically and domestically, with Taiwan’s international credibility at stake. But Lai’s message was exactly
RSS