Large-scale human engineering of the Earth’s climate to prevent catastrophic global warming would not only be ineffective, but would have severe unintended side effects and could not be safely stopped, a comparison of five proposed methods has concluded.
Science academies around the world, as well as some climate activists have called for more research into geoengineering techniques, such as reflecting sunlight from space, adding vast quantities of lime or iron filings to the oceans, pumping deep cold nutrient-rich waters to the surface of oceans and irrigating vast areas of the north African and Australian deserts to grow millions of trees. Each method has been shown to potentially reduce temperature on a planetary scale.
Yet researchers at the Helmholtz Centre for Ocean Research in Kiel, Germany, modeled these five potential methods and concluded that geoengineering could add chaos to complex and not fully understood weather systems. Even when applied on a massive scale, the most that could be expected, they say, is a temperature drop of about 8 percent.
The potential side effects could be disastrous, say the scientists, writing in Nature Communications. Ocean upwelling, or the bringing up of deep, cold waters, would cool surface water temperatures and reduce sea ice melting, but would unbalance the global heat budget, while adding iron filings or lime would affect the oxygen levels in the oceans. Reflecting the sun’s rays into space would alter rainfall patterns and reforesting the deserts could change wind patterns and could even reduce tree growth in other regions.
In addition, the scientists say, two of the five methods considered could not be safely stopped.
“We find that, if solar radiation management or ocean upwelling is discontinued then rapid warming occurs. If the other methods are discontinued, less dramatic changes occur. Essentially all of the carbon dioxide that was taken up remains in the ocean,” they say.
Even the foresting of deserts on a massive scale could prove disastrous if the irrigation needed to grow the trees were stopped, they say.
“The desert regions would eventually return to desert and the carbon that was stored in the plant biomass and soil would slowly be returned to the atmosphere through decay and respiration,” the paper says.
Each of the five climate engineering methods considered has advantages and disadvantages, but individually they are all limited, say the authors.
“If carbon dioxide emissions remain high, the climate engineering methods ... should not be solely counted on to prevent warming. Our results suggest that carbon dioxide mitigation seems the most effective way to prevent climate change. Climate engineering does not appear to be an alternative option, although it could be possibly used to complement mitigation,” say the authors, who do not look at the ethical, economic, legal, political or technological feasibility of the five methods.
“The paper sounds a timely warning about the abject stupidity of relying upon climate-engineering solutions when reducing our reliance on carbon-based energy systems is the only sensible option,” said Matt Watson, a lecturer in geophysical natural hazards at the UK’s Bristol University.
CONFRONTATION: The water cannon attack was the second this month on the Philippine supply boat ‘Unaizah May 4,’ after an incident on March 5 The China Coast Guard yesterday morning blocked a Philippine supply vessel and damaged it with water cannons near a reef off the Southeast Asian country, the Philippines said. The Philippine military released video of what it said was a nearly hour-long attack off the Second Thomas Shoal (Renai Shoal, 仁愛暗沙) in the contested South China Sea, where Chinese ships have unleashed water cannons and collided with Philippine vessels in similar standoffs in the past few months. The China Coast Guard and other vessels “once again harassed, blocked, deployed water cannons, and executed dangerous maneuvers” against a routine rotation and resupply mission to
GLOBAL COMBAT AIR PROGRAM: The potential purchasers would be limited to the 15 nations with which Tokyo has signed defense partnership and equipment transfer deals Japan’s Cabinet yesterday approved a plan to sell future next-generation fighter jets that it is developing with the UK and Italy to other nations, in the latest move away from the country’s post-World War II pacifist principles. The contentious decision to allow international arms sales is expected to help secure Japan’s role in the joint fighter jet project, and is part of a move to build up the Japanese arms industry and bolster its role in global security. The Cabinet also endorsed a revision to Japan’s arms equipment and technology transfer guidelines to allow coproduced lethal weapons to be sold to nations
Thousands of devotees, some in a state of trance, gathered at a Buddhist temple on the outskirts of Bangkok renowned for sacred tattoos known as Sak Yant, paying their respects to a revered monk who mastered the practice and seeking purification. The gathering at Wat Bang Phra Buddhist temple is part of a Thai Wai Khru ritual in which devotees pay homage to Luang Phor Pern, the temple’s formal abbot, who died in 2002. He had a reputation for refining and popularizing the temple’s Sak Yant tattoo style. The idea that tattoos confer magical powers has existed in many parts of Asia
ON ALERT: A Russian cruise missile crossed into Polish airspace for about 40 seconds, the Polish military said, adding that it is constantly monitoring the war to protect its airspace Ukraine’s capital, Kyiv, and the western region of Lviv early yesterday came under a “massive” Russian air attack, officials said, while a Russian cruise missile breached Polish airspace, the Polish military said. Russia and Ukraine have been engaged in a series of deadly aerial attacks, with yesterday’s strikes coming a day after the Russian military said it had seized the Ukrainian village of Ivanivske, west of Bakhmut. A militant attack on a Moscow concert hall on Friday that killed at least 133 people also became a new flash point between the two archrivals. “Explosions in the capital. Air defense is working. Do not