Hot topics: US scientists gather in Chicago
Global warming and the future of agricultural were two of the issues discussed at the recent conference of the American Association for the Advancement of Science. Keith Kloor reports.
Gloom over meeting climate targets
Climate scientists tell us the future is clear: either we kick our fossil fuel addiction by mid-century or we seriously risk burning up the planet. World leaders pay lip service to this dire challenge. But the larger conundrum remains: how do we decarbonise a global industrial economy while keeping the lights on?
That was the question tackled by a panel of energy experts at this year’s American Association for the Advancement of Science (AAAS) conference in Chicago. The symposium was called, “Is it possible to reduce 80% of greenhouse gas emissions by 2050?” That’s the target climate scientists believe needs to be met to avert catastrophic climate change.
Theoretically, it can be done, asserted Stanford’s Mark Jacobson, a renewable energy expert who insisted it was possible to power the planet with just wind, solar, and hydro sources. The effort would require 3.8 million wind turbines spread across the globe, he said.
But the other panellists were far from convinced, especially since Jacobson leaves nuclear power out of his zero carbon energy equation. “It’s a matter of basic common sense that when you have a very difficult task like this, the more options that are available, the more likely you are to succeed,” argued Richard Lester, head of the Department of Nuclear Science and Engineering at the Massachusetts Institute of Technology (MIT).
Climate scientist James Hansen once famously derided the notion that fossil fuels could be supplanted solely by renewables as akin to “believing in the Easter bunny and the tooth fairy”. Many experts agree, largely because wind and solar is too intermittent and because the technology will take too long to scale up.
So 100% renewable energy might generally be considered out of the question, but what about the 80% target? In 2012, the US government’s National Energy Research Lab reported that, with smart grid technology and a diverse portfolio of renewable energy sources, 80% energy from renewables could keep the country reliably lit in 2050 – if it was prepared to pay to get there.
Adding nuclear into the equation would bring the target closer to our reach, Hansen argues. In an opinion piece published online in February, he reiterated his case for China and the US to co-operate on advanced nuclear power technology. He is particularly scornful of anti-nuclear activists, warning: “If they are allowed to continue to spread misinformation about nuclear power, it is unlikely that we can stop expanded hydro-fracking, continued destructive coal mining, and irreversible climate change.”
Except for Jacobson’s sunny, can-do attitude, the mood at the AAAS session was gloomy about the prospects for reducing greenhouse gases by 80% by mid-century. The main barrier? Money. As Lester noted in his talk, “The energy problem would be easier if we didn’t also care about economic growth.”
Feed the world, wreck the planet?
Can we feed the world without destroying the planet? The question was once again in focus at this year's AAAS conference, with plenty to consider since it was last raised in 2010. Since then concerns about food security have only increased, driven in part by periodic spikes in food prices that triggered political unrest in the Middle East and elsewhere.
But it’s the future that most worries experts, specifically around mid-century when the global population will reach approximately 9 billion people. As University of Minnesota ecologist Jonathan Foley put it at that 2010 AAAS panel, “Feeding the world while preserving the environment is maybe the greatest challenge we will ever face."
This year, several panels explored the nexus of food security and environmental sustainability. One session discussed how global food production will be severely tested by multiples stressors, from climate change (such as more frequent severe weather extremes) to water limitations. Another session emphasised the need to ramp up public research and development, in order to improve the productivity of agricultural seeds. Felix Kogan, a panellist and research scientist with the US National Oceanic and Atmosphere Organization (NOAA), bluntly stated: “We need a new green revolution.”
But some leading environmental scientists, such as Foley, are sceptical about the potential of agricultural biotechnology that will create seeds capable of dealing with hotter, drier conditions. In a recent widely circulated essay, Foley says that, “it may be a long while before these crops are ready for the real world. Why not put more effort into improved agronomic approaches—such as using cover crops, mulching and organic-style techniques—instead, which could yield results today?”
Critics respond that there is no reason why these two different pathways can’t coexist. Additionally, as Ramez Naam, author of the critically acclaimed 2013 book, The Infinite Resource: The Power of Ideas on a Finite Planet, wrote in a rebuttal to Foley: “One of the reasons that GM crops haven’t done more to boost food security around the world is that non-scientific bans have blocked them from doing so.”
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