Engineers: You Can Disrupt Climate Change

Seven years ago, we published an article in IEEE Spectrum titled “What It Would Really Take to Reverse Climate Change.” We described what we had learned as Google engineers who worked on a well-intentioned but ultimately failed effort to cut the cost of renewable energy. We argued that incremental improvements to existing energy technologies weren’t enough to reverse climate change, and we advocated for a portfolio of conventional, cutting-edge, and might-seem-crazy R&D to find truly disruptive solutions. We wrote: “While humanity is currently on a trajectory to severe climate change, this disaster can be averted if researchers aim for goals that seem nearly impossible. We’re hopeful, because sometimes engineers and scientists do achieve the impossible.”

Today, still at Google, we remain hopeful. And we’re happy to say that we got a few things wrong. In particular, renewable energy systems have come down in price faster than we expected, and adoption has surged beyond the predictions we cited in 2014.

Our earlier article referred to “breakthrough” price targets ( modeled in collaboration with the consulting firm McKinsey & Co.) that could lead to a 55 percent reduction in U.S. emissions by 2050. Since then, wind and solar power prices have met the targets set for 2020, while battery prices did even better, plummeting to the range predicted for 2050. These better-than-expected price trends, combined with cheap natural gas, caused U.S. coal usage to drop by half. The result: By 2019, U.S. emissions had fallen to the level that the McKinsey scenario forecast for 2030—a decade sooner than our model predicted.

And thanks to this progress in decarbonizing electricity production, engineers are seeking and finding numerous opportunities to switch existing systems based on the combustion of fossil fuels to lower-carbon electricity. For example, electric heat pumps are becoming a cost-effective replacement for heating fuel, and electric cars are coming down in ­­price and going up in range.

Even with all this progress, though, we’re still on a trajectory to severe climate change: a 3 °C rise by 2100. Many countries are not meeting the emissions reductions they pledged in the 2015 Paris Agreement. Even if every country were to meet its pledge, it would not be enough to limit planetwide warming to 1.5 °C, which most experts consider necessary to avoid environmental disaster. Meeting pledges today would require a drastic slashing of emissions. If these wholesale emission reductions don’t happen, as we think likely, then other strategies will be needed to keep temperatures within bounds.

Here are some key numbers: To reverse climate change, even partially, we’ll need to bring atmospheric carbon dioxide levels down to a safer threshold of 350 parts per million; on Earth Day 2021 the figure stood at 417 ppm. We estimate that meeting that target will require removing on the order of 2,000 gigatonnes of CO₂ from the atmosphere over the next century. That wholesale removal is necessary both to draw down existing atmospheric CO₂ as well as the CO₂ that will be emitted while we transition to a carbon-negative society (one that removes more carbon from the atmosphere than it emits).

Our opening battles in the war on climate change need engineers to work on the many existing technologies that can massively scale up. As already illustrated with wind, solar, and batteries, such scale-ups often bring dramatic drops in costs. Other industrial sectors require technological revolutions to reduce emissions. If you experiment with your own mix of climate-mitigation techniques using the En-ROADS interactive climate tool, you’ll see how many options you have to max out to change our current trajectory and achieve 350 ppm CO₂ levels and a global temperature rise of no more than 1.5 °C.

So what’s an engineer who wants to save the planet to do? Even as we work on the changeover to a society powered by carbon-free energy, we must get serious about carbon sequestration, which is the stashing of CO₂ in forests, soil, geological formations, and other places where it will stay put. And as a stopgap measure during this difficult transition period, we will also need to consider techniques for solar-radiation management—deflecting some incoming sunlight to reduce heating of the atmosphere. These strategic areas require real innovation over the coming years. To win the war on climate change we need new technologies too. [READ MORE]