Carbon dioxide indirectly causes up to 50 percent more global warming than originally thought, a finding that raises questions over targets for stabilizing carbon emissions over the long term, a study said yesterday.
In a paper published in the journal Nature Geoscience, British scientists said a tool commonly used in climate modeling may have miscalculated the sensitivity of key natural processes to the warming caused by carbon dioxide.
As a result, calculations for man-made global warming on the basis of carbon emissions may be underpitched by between 30 and 50 percent, they said.
PHOTO: REUTERS
The study was published on the eve of a 12-day UN conference in Copenhagen aimed at providing a durable solution to the greenhouse-gas problem.
The authors said the more-than-expected warming would unfold over a matter of hundreds of years, rather than this century.
The findings do not mean that the predictions for temperatures by 2100 established by the UN’s Intergovernmental Panel on Climate Change (IPCC) should be rewritten, they said.
“We don’t want to be overly alarmist here,” said lead author Dan Lunt of the University of Bristol. “But if people are thinking about stabilizing CO2 at a certain atmospheric level, or putting together a treaty, or having a debate about what the levels should be, it really is important to know what the long-term consequences of those emissions are going to be, because CO2 hangs around for so long.”
Lunt and colleagues tested a widely used climate model on an epoch called the mid-Pliocene warm period, about 3 million years ago, when Earth heated up in response to natural processes.
Cores drilled from ocean sediment provide a good idea about atmospheric carbon levels and temperature at the time.
What the team found, though, was that the CO2 levels in the Pliocene — around 400 parts per million — were not consistent with the warming, which was around 3ºC higher than today.
The difference could only be fully explained by the long-term loss of icesheets and changes in vegetation, the paper says. These changes cause Earth’s surface to absorb more solar radiation, which causes more warming, and so on.
When applied to what awaits us this century, the adjusted model suggests that nothing significantly different will happen compared to what has already been estimated.
“In that time scale, we don’t think the Greenland icesheet is going to melt completely or that East Antarctica will melt. That was what we saw in the model for 3 million years ago, but it is unlikely to take place in the nextcentury,” Lunt said.
Where it poses a dilemma, though, is how to fix a target for stabilizing emissions so that future generations are not hit by this long-term warming mechanism.
One goal is to limit warming since pre-industrial times to 2ºC. Lunt says that today’s level may already be too high in this context.
NO-LIMITS PARTNERSHIP: ‘The bottom line’ is that if the US were to have a conflict with China or Russia it would likely open up a second front with the other, a US senator said Beijing and Moscow could cooperate in a conflict over Taiwan, the top US intelligence chief told the US Senate this week. “We see China and Russia, for the first time, exercising together in relation to Taiwan and recognizing that this is a place where China definitely wants Russia to be working with them, and we see no reason why they wouldn’t,” US Director of National Intelligence Avril Haines told a US Senate Committee on Armed Services hearing on Thursday. US Senator Mike Rounds asked Haines about such a potential scenario. He also asked US Defense Intelligence Agency Director Lieutenant General Jeffrey Kruse
STUMPED: KMT and TPP lawmakers approved a resolution to suspend the rate hike, which the government said was unavoidable in view of rising global energy costs The Ministry of Economic Affairs yesterday said it has a mandate to raise electricity prices as planned after the legislature passed a non-binding resolution along partisan lines to freeze rates. Chinese Nationalist Party (KMT) lawmakers proposed the resolution to suspend the price hike, which passed by a 59-50 vote. The Taiwan People’s Party (TPP) voted with the KMT. Legislative Speaker Han Kuo-yu (韓國瑜) of the KMT said the resolution is a mandate for the “immediate suspension of electricity price hikes” and for the Executive Yuan to review its energy policy and propose supplementary measures. A government-organized electricity price evaluation board in March
NOVEL METHODS: The PLA has adopted new approaches and recently conducted three combat readiness drills at night which included aircraft and ships, an official said Taiwan is monitoring China’s People’s Liberation Army (PLA) exercises for changes in their size or pattern as the nation prepares for president-elect William Lai’s (賴清德) inauguration on May 20, National Security Bureau (NSB) Director-General Tsai Ming-yen (蔡明彥) said yesterday. Tsai made the comment at a meeting of the Legislative Yuan’s Foreign Affairs and National Defense Committee, in response to Democratic Progressive Party (DPP) Legislator Wang Ting-yu’s (王定宇) questions. China continues to employ a carrot-and-stick approach, in which it applies pressure with “gray zone” tactics, while attempting to entice Taiwanese with perks, Tsai said. These actions aim to help Beijing look like it has
China is mischaracterizing UN Resolution 2758 for its own interests by conflating it with its “one China” principle, US Deputy Assistant Secretary for China and Taiwan Mark Lambert said on Monday. Speaking at a seminar held by the German Marshall Fund, Lambert called for support for Taiwan’s meaningful participation in the international community at a time when China is increasingly misusing Resolution 2758. The resolution had a clear impact when it changed who occupied the China seat at the UN, Lambert said. “Today, however, the PRC [People’s Republic of China] increasingly mischaracterizes and misuses Resolution 2758 to serve its own interests,” Lambert said. “Beijing