Oranges in the supermarket. Sewage treatment plants. Theme parks, ski lifts, skating rinks in summer. Highways, airports, train stations, logistics centres. And cars. Cars take us to work, to meetings with friends, to the theatre, to sports venues, to our holiday destination.

These are pieces of the world that keep seven billion people busy, reasonably healthy, and fed. It only functions because we use vast amounts of energy to move stuff around, heat it up, and cool it down. Most of that energy comes from coal, oil, and natural gas.

Meanwhile, greenhouse gas emissions are rapidly returning our climate to what it was at the time of the dinosaurs, before trees and time took a few billion tons of carbon out of the air and put it underground. That ancient climate may be good for mosquitos and crocodiles, but it is not the one our own species evolved to live in. It is not the one in which we developed crops and irrigation channels to farm the land, or built coastal cities like Venice and New York and Jakarta, which are going to be under water unless we build giant walls around them.

Tackling the problem at the source
Most of our emissions come from energy consumption, so it’s tempting to think that if we adjust our lifestyles to use less energy, this will solve the problem. It will not. The science is clear. To preserve the environment that our species and society are adapted to, we need to end greenhouse gas emissions entirely, from all human activity, within forty years. Thirty, to be on the safe side. We simply can’t reduce energy consumption far enough, fast enough, to stop climate change, not if seven billion people, most of them living in cities, are going to eat. We don’t solve climate change by using less energy. We solve it by using different energy.

The science shows this can work. Globally and on every continent, there is far more renewable energy available than modern society could ever consume. The land needed to supply all of our current energy consumption with wind, solar, and hydropower is a tiny fraction of what we use for agriculture, and could easily be located in places where crops won’t grow. Innovative technologies have brought down capital costs and made renewable energy competitive. It costs about five centimes per kilowatt-hour to generate electricity from wind or sunshine, as little as one or two centimes in really windy or sunny places. The required transmission and storage can add another three or four centimes to average costs. Fossil energy exceeds ten centimes, whether it is electricity at a new power plant or heat produced in a building or car engine. With or without a carbon tax, the math is in renewable energy’s favour, and it is getting better every year.

Daring to take the first step
If renewable energy is really this good, why does it seem like people hesitate to use it? The answer lies in the enormous complexity of our infrastructure. No matter how fast we want to reduce emissions – and every opinion poll shows that most people want this – we first need to replace a century’s worth of capital investment that was designed to get fossil fuels out of the ground and into our cars, homes, and factories. Renewable energy requires different infrastructure, in some cases simpler and in other cases more complicated. To get this stuff planned, built, and operating reliably, governments need to provide different incentives, regulations, and institutional support. It all takes time.

But this is still a race we can win. Last year, over three-quarters of global investment into new energy supply went into renewables, continuing a trend of exponential growth. Solar and wind have gone from supplying 0.3% of Europe’s total energy use in 2000 to over 4% today. That’s a twelvefold increase in 17 years, and with another twelvefold increase we are up to 50% renewables, well on our way to 100%. Of course, these numbers also mean that over 95% of our energy is still coming from other sources, mostly fossil. It can seem like nothing has changed. Don’t be fooled.

Electric mobility as climate change stopper
Electric cars play a decisive role in the effort to stop climate change. Because they let us drive with renewable energy. They are almost certainly the only way we could all be doing so within 30 years, whether or not our cars are autonomous, privately owned or shared, and whether or not we drive them less. True, scientists can use solar energy to extract CO2 from the air, split it, and combine the carbon with hydrogen from water to synthesise alternative fuel. But the chemical reactions are inefficient, and at least a decade away, more likely two, from being remotely affordable, before we could start to scale them up. What about biofuels? They demand vastly more land and water than wind or solar, and couldn’t power even a fraction of the cars on the road, not without chopping down rainforests or making people go hungry. Hydrogen fuel cells? They would require an entirely new network of hydrogen production and pumping stations before anybody could drive them anywhere, and that means ten or fifteen years before fuel-cell cars could even begin to take off. Electric cars started taking off five years ago, their market share growing at 40% per year, charging off the power grid we already have.

Electric cars – accelerators of change
Electric cars used to demand personal sacrifice. Today they offer faster acceleration, better handling, less maintenance, and in most cases lower ownership costs than the petrol equivalent. Without a second thought, you plug in your car where you park overnight, like your phone. Newer models offer 300 – 600 km of range. If that isn’t enough, your touchscreen will unlock thousands of high-speed public charging boxes, an inconspicuous network that already exists and is growing. In Norway, where government policies promote them most aggressively, electric cars account for close to half of the new car market. China is headed there soon. Do we want to join them?

As with renewable energy, we can let electric cars take their course, or we can do everything possible to speed things up. Let them take their course, and the world will take its course as well. It may well become one without glaciers or ice caps, with massive ecosystem loss, disrupted food supplies, and environmental refugees. Moving faster will take some effort but leave us better off in every way. In fifteen years, we could reach the point where all new cars are electric, adding convenience and saving money. In thirty years, electric cars could be the only ones left on the road, except for the occasional antique running on alternative fuel, and our cities would be cleaner and quieter. Within those same thirty years we could be producing all the renewable energy needed to manufacture and power those cars, as well as manufacture and power everything else. We will have solved our generation’s greatest environmental challenge. The choice is ours, and it is here today. I say, bring it on!