Lawrence Cathles wants you to stop worrying.

The day-to-day discourse surrounding climate change may say differently. Whether it's stories on drought-stricken farmers or coastal communities retreating from rising seas, most climate news seems to focus on how doomed we are. The climate is warming, seas are rising and the planet's rapidly expanding population is living an unsustainable lifestyle.

But Cathles thinks we have reasons to be hopeful. In an essay published in September by the Geological Society of London, the Cornell University geologist writes that the Earth has not only enough resources to sustain humanity, but also enough to facilitate a transition to clean energy and sustain a population increase up to 10.5 billion by 2100.

In his visions of the future, Cathles has a tendency to go first class. The 10.5 billion earthlings would each enjoy the current European standard of living.

Lawrence Cathles

In short, this future includes harvesting resources from the oceans and using natural gas to bridge from fossil fuel resources to a combination of nuclear and renewable power.

Ultimately, Cathles thinks Earth is in a much more secure position than we are often led to believe. "The issue is really what we do," he said in an interview. "We can talk ourselves out of a future if we want to."

Deep-sea mining potential

A central theme of Cathles' arguments is his opinion that humanity isn't sucking the planet dry of resources and isn't likely to do so for hundreds of centuries even as the population rises above 10 billion.

We can count on the oceans, Cathles writes, for vast reserves of uranium, manganese, lithium and other minerals, as well as water than can be desalinated and used for drinking and irrigation. And while he concedes ocean-floor mining may be expensive at first, he said demand would soon make it feasible for extracting numerous resources.


But it may not be that simple, according to Brian Skinner, a geophysicist at Yale University. "If you make a mistake in the sea, that mistake spreads very widely, very quickly," he warned.

"I don't think that we would ever be drawing a very large amount of our resources from the sea," he added.

But resources from the ocean may be necessary to achieve Cathles' vision of 10.5 billion people living, sustainably, at a European standard of living.

A huge buildout of nuclear energy

The world currently consumes about 15 terawatts of power each year for all purposes. Cathles estimates that, to achieve a European standard of living for 10.5 billion people, that number would increase to about 75 TW a year.

That still only averages out to a growth rate of 1.6 percent per year from now until 2100, but even that much added capacity would require tremendous infrastructure development if the world is to transition completely off fossil fuels by 2100.

Supplying that kind of power with solar panels would require concentrating panels in 30 percent of the nonpolar desert area of the world -- to power Europe, alone you'd need panels blanketing a desert twice the size of Poland.

What's more, Cathles writes that solar and wind power will continue to run into distribution challenges, namely difficulty transmitting the power to remote areas.

Alternatively, Cathles writes, 22,272 nuclear power stations could be built to generate 3.3 gigawatts each per year. With a larger population and a more urgent incentive, he writes, "the scale of construction is not daunting."

"Never underestimate what large numbers of humans can do," he says in the essay.

There is more than enough uranium in the oceans to keep all these plants humming, he said, and proliferation could be avoided by using thorium to power the reactors, instead of uranium-238, which creates plutonium, a nuclear weapons material. The only obstacle would be the ongoing political hesitancy, in the wake of the Fukushima Daiichi disaster and proliferation concerns.

Skinner said that with "sensible, careful site selection," many of the concerns with nuclear plants can be eliminated. Still, it might take some time for nuclear to regain its popularity.

"It's not politically the most feasible option right now," Cathles said, "but down the line it could well be."

'Overselling' natural gas?

For the next few decades, Cathles recommends using natural gas to bridge from dirtier fossil fuels like coal and oil to clean, renewable energy. It's a popular theory, voiced by many high-profile policymakers including U.S. Energy Secretary Ernest Moniz (EnergyWire, March 5).

Cathles writes that society, especially the West, should aim to transition from oil and coal to natural gas by 2050, then begin transitioning from natural gas to nuclear and renewable power. Critics question this approach because burning natural gas will still add carbon dioxide to the atmosphere, and once it runs out, there's no guarantee society won't just go back to burning dirtier fossil fuels.

Raymond Pierrehumbert, a geophysicist at the University of Chicago, wrote in an email that Cathles "oversells gas as a bridge fuel."

"Without strong policies on carbon, gas just bridges a coal-powered past to a coal-powered future," he added.

Cathles doesn't agree. Last year, he got into a fairly public argument with fellow Cornell professor Robert Howarth over the greenhouse gas emissions from hydraulic fracturing used to extract natural gas, and he maintains his position in this essay that natural gas has a much lighter carbon footprint than fossil fuels like coal.

He also said the planet would stop burning natural gas by 2100 either because cleaner alternatives are ready or because there's no gas left. "It can't last too long, it can't last more than 100 years," he said, "but 100 years is significant."

All's well that ends well

Needless to say, Cathles still must contend with a chorus of skeptics beginning with one on his own campus. David Pimentel, a professor emeritus in entomology at Cornell, said he and Cathles have "about a 180-degree difference in views."

Pimentel, as far back as 1994, has said Earth's sustainable population was as low as 2 billion.

Pierrehumbert added that some assumptions in the essay are "wildly optimistic," particularly regarding the assumption that fossil fuel use will begin declining by 2050. "That is clearly possible, but I don't see the political system moving in the direction that is needed," Pierrehumbert said.

But no one appears to disagree with Cathles' assessment that pessimism won't help things. Pierrehumbert said that "despair is not an option." He added: "Everybody is going to have to work as hard as possible to even have a chance of success, and that has to be done even if we consider the chances of success to be small."

Cathles said universities need to play a bigger role in this regard by being motors for solving problems rather than raising problems, but he added that's not usually the best way to get funded.

Ultimately, with the world's population continuing to climb -- and 10.5 billion by 2100 looks more likely each year -- society will have to find some way to live sustainably sooner rather than later to avoid a climate change catastrophe, the scientists agreed.

Some changes are already underway, such as sea-level rise and ocean acidification, but humanity still has time to adapt and expand the world population, fully power developing regions of the world, and not destroy the planet in the process.

"The human race is infinitely adaptable," said Skinner, before adding, "No, not 'infinitely.' Is 'exceptionally' adaptable."