The news that today’s power plants and transportation systems are probably not enough to doom the planet to catastrophic climate change feels a bit like our last warning.

A study in the current issue of the journal Science projects that future carbon dioxide emissions from existing fossil fuel sources would, by themselves, leave the atmospheric CO2 concentration at 450 parts per million and therefore global warming at under 2°C by 2060. This level is probably enough to avoid catastrophic climate change (though not necessarily dangerous climate change).

The problem, as the study’s authors note, is that we’re rapidly adding coal-fired power plants and oil-burning vehicles. The demand for energy is rising, most notably in China, and it will take a phenomenal effort to meet all of the new demand with carbon-neutral energy sources.

I’d love to see a follow-on study that projects the mix of new power generation and transportation systems that are likely to come online between now and 2050 under multiple scenarios, and then projects the consequences for climate change between now and the end of the century.

I suspect that the median scenario would be pretty scary and even the rosiest projection would leave a lot to be desired.

But this study could be telling us that it’s not too late. A story about the study in Scientific American points out the stakes:

The U.S. still generates half of its electricity via coal burning—and what replaces those power plants over the next several decades will play a huge role in determining the ultimate degree of global climate change.

That means the decisions we make in the next few years — the remainder of President Obama’s first term — could make all the difference.