Achieve something spectacular and it’s only natural to want to do it again. That is one reason why Nasa has periodically begged the US Congress for the funds to go back to the moon and on to Mars.
One day the money will be found. One day astronauts will look back on our planet again from beyond Earth orbit. Like those who went before, they will be awed by the sight of it hanging in the abyss, wreathed in the fragile life support system of oceans and air. Unlike the Apollo crews, they will be looking at a planet in the grip of a man-made health emergency. Compared with 50 years ago, Earth is in bad shape.
The frequency of severe storms, droughts and forest fires has doubled; that of floods has quadrupled. In 2016, an Oxford University study estimated that climate change could be killing half a million people a year as a result of reduced crop yields. Average temperatures have only risen since then. Glaciers are in full retreat. For these reasons and others, Michael Bloomberg, the billionaire and former New York City mayor, urged the graduating class of 2019 at the Massachusetts Institute of Technology, in their commencement address last month, to make their moonshot saving their own planet from climate change.
It was a zinger of a speech, delivered to some of the brightest students in the world.
Bloomberg was surely right about priorities. He was probably also right to say the biggest challenge in confronting climate change is not scientific or technological but political. But this is not simply because one US administration refuses to hear what climate science has to say.
The scale of the transition to be made to a world economy powered by clean energy rather than fossil fuels requires more courage from everyone. Efficiency alone – using less energy per capita – won’t cut it. Geo-engineering – interfering with climate systems to slow global warming; the subject of a Tortoise ThinkIn tonight – probably won’t either. The cost of direct air capture, for instance, is too high for now to make it feasible at scale.
A new study suggests that reforesting an area the size of the United States could remove from the atmosphere between one and two thirds of all the CO2 we have put there since the start of the industrial age. But who will earmark the land for trees? And who will make sure that growing them doesn’t make us more complacent about our emissions rather than less?
Bloomberg has pledged $500 million of his own money to speed up the phasing out of coal and oil. It’s a start. Ultimately, though, today’s students will have to decarbonise a global energy network at a cost estimated by the International Energy Agency to be $44 trillion. The upside is that building the new network of renewable and nuclear power sources that must replace the old one, and the clean energy storage systems that must replace every petrol station and pipeline on the planet, should create more wealth than it costs. That, too, is an IEA projection, although it won’t come true without extraordinary leadership.
It was Frank Borman in the Apollo 8 command module who closed his crew’s reading of Genesis with the words, “God bless all of you, all of you on the good Earth”. If we can’t look after the good Earth, what business do we have exploring space?