Solar, wind and nuclear power are already good alternatives to fossil fuels, and now a promising new contender is emerging. ‘Geothermal’ power was once limited to countries with hot volcanic rock near the surface (Italy, Iceland, New Zealand), but now start-ups are going deep and doing a different kind of ‘fracking’.

At four km. down there’s hot, dry rock (200-400° C) under half the land surface of the planet. Use high-pressure water to fracture the rock, and the water flashes into super-heated steam. It spins turbine blades to create electricity, then cools and is pumped back down to go around again.

This technology could end up bigger than solar or wind, because it’s not ‘intermittent’: it produces electricity day and night in any weather. The first megawatt-scale pilot plant opened in Nevada last year.

We can get a long way towards solving our energy dilemma even with the current clean energy sources, but to finish the job we will require fossil-free sources of ‘base load’ power, and it’s good to know that in the longer run they will be available. In the meantime we need two other key technological fixes, and they, too, are appearing on the horizon.

The highest non-energy priority is a global-scale solution for the accelerating loss of biodiversity. That can only be achieved by returning at least half the land human beings have appropriated for agriculture back to its natural state – and almost miraculously, such a solution has appeared.

It’s called ‘precision fermentation’: put the right microbe in a bioreactor, give it water, carbon dioxide, hydrogen and sunlight, and it will double its mass every three hours. Drain the resultant soup off, dry it, and you have 65% edible protein, fats or carbohydrates. You can also turn it into appetising food for people, but the first big prize is animal feed.

Half the world’s farmland is used to feed our domestic animals. We could feed them this instead and re-wild most of that land. (The cattle won’t mind a bit.) And if our own food supply shrinks as the temperature rises, we can eat the ‘food from the sky’ too: it can be turned into any kind of food you want. The first factory opens near Helsinki this year.

But the typical new technology takes 15-30 years to roll out at scale, and there is little reason to believe that these new technologies are different. Given how fast the warming is proceeding already, and the near-certainty that we will cross ‘tipping points’ and unleash ‘feedbacks’ that speed the warming further, we are still in great danger.


That’s why we will probably need Solar Radiation Management (SRM). This involves reducing the amount of sunlight reaching the planet’s surface just by one or two percent, in order to keep the heating below +2° C while we work to reduce our emissions. It’s not a solution, but it may be a necessary stopgap measure to avoid political and economic chaos.

SRM is all about reflecting sunlight back into space, but it comes in several flavours. The leading candidate involves using special aircraft to put sulphur dioxide high into the stratosphere.

Big volcanoes do exactly that from time to time, and it temporarily cools the Earth’s surface without harming living things. (There is no life in the stratosphere.) Some worry that it might expand the ozone hole, but experts tell me that at worst it might slow the healing of the ozone hole. It wouldn’t actually expand it.

Alternatively (or in addition), we could build unmanned vessels that spray a fine mist into the clouds near the ocean surface and thicken them so they reflect more sunlight. We haven’t yet built the planes and ships to do these jobs, but we probably will.

Forty-five years ago James Lovelock, the scientist who realised that all the Earth’s natural systems are connected and named the ensemble ‘Gaia’ (now renamed ‘Earth System Science’ in the universities) saw this all coming.

He knew that we would be too slow in cutting our emissions, because that’s how human beings are. He foresaw that we would then have to intervene directly in the climate to save ourselves, and predicted that we would become ‘planetary maintenance engineers’.

I interviewed him one last time for my new book on climate change, just eight months before he died in 2022 at the age of 103. “Are we there yet, Jim?” I asked him. “Yes,” he said, but he wasn’t in despair. We have the tools to get through this if we use them wisely.


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Gwynne Dyer is an independent journalist whose articles are published in 45 countries.

Gwynne Dyer