On Thursday 9 February the Institute for Policy Research (IPR) welcomed Astronomer Royal Lord Rees to lecture on The World in 2050 and Beyond. In his talk, which concerned medium- and long-term threats to humanity, the life peer drew not only on his experience as an astronomer and scholar at the University of Cambridge, but also on his work as founder of the University’s Centre for the Study of Existential Risk. The picture he painted was of a world on the tipping point between great advances and great catastrophe.

After a short introduction from IPR Director Professor Nick Pearce, Lord Rees began with the observation that the current century is very special. “It’s the first when one species, ours, has the planet’s future in its hands”, he said. “We could irreversibly degrade the biosphere, we could trigger the transition from biological to electronic intelligences. Or misdirected technology – bio or cyber – could cause a catastrophic setback to civilisation.” Many of these threats proceed from conscious decisions, but the astronomer also highlighted the long-term threats that are presented by our “ever-heavier collective footprint” on the Earth.

Urbanisation and population growth are driving this impact, he pointed out. World population has grown from 3bn in the mid-20th century to over 7bn today; by 2050, there will be 9bn – and 70 per cent of them will live in cities. Changes in lifestyle, governance and food production will be essential to cope with this growing burden, and to prepare for an uncertain long-term future. The concomitant loss of biodiversity, which may well be accelerated by these trends, must also be considered. On rising extinction rates, Lord Rees commented: “We’re destroying the book of life before we’ve read it”.

Another related issue is climate change. Most would agree, he said, that regional disruptions to weather will put greater pressure on food production in the decades to come – and that it is impossible to rule out catastrophic effects of global warming being felt by the end of the century. The best policy response to this challenge remains the subject of debate, however, depending on the value one places on the lives of people living now, and those who will live in the uncertain future; the Astronomer Royal summarised the opposing views of those who prioritise climate action now, and those who believe the solution is to work on more immediate problems.

One measure which Lord Rees supported for reducing carbon emissions was to invest in the research and development of low-carbon technologies, and this provided the perfect segue into the next threat he perceived: the accelerating pace of technological advancement. The same microbiological experiments that improve diagnostics, vaccines and antibiotics also demonstrate how super-pathogens could be engineered; this science could prevent a pandemic – or create one. Gene editing techniques, similarly, offer promise – but Chinese experiments on human embryos and the possibility of unintended consequences cast a shadow on progress. In research, Lord Rees observed, “whatever regulations are imposed, on prudential or ethical grounds, can’t be enforced worldwide – any more than the drug laws can, or the tax laws. Whatever can be done will be done by someone, somewhere.”

Progress in AI, robotics and digital technology has been manifest, the life peer pointed out – particularly in the machine learning techniques that allowed computers to beat human champions at complex games like go and, more recently, poker. But advances are inconsistent; “robots are still clumsier than a child in moving pieces on a real chessboard”, he said. “They can’t tie your shoelaces or cut old people’s toenails.” The prospect of widespread technological unemployment is therefore a problem for the long-term – but still one worthy of consideration, along with the prospect of humans living side-by-side with autonomous robots.

Regardless of the role they may come to assume in human society, and the responsibilities which their human creators may or may not have to them, robots will certainly play a role in expanding humanity’s influence beyond our planet, Lord Rees said. Expectations of mass emigration from Earth, however, he called dangerous and delusional; “there is no Planet B”, he warned.

Lord Rees concluded his talk with advice for scientists on how they could begin to work with politicians and policymakers to defend humanity from these challenges. He contrasted President Obama’s assertion that policymakers should heed the advice of scientists “even when it is inconvenient – indeed, especially when it is inconvenient” with concerns about the new regime, and praised the rapport and respect between UK scientists and politicians. Nonetheless, “scientists might have more leverage on politicians indirectly”, Lord Rees suggested, “by campaigning, so that the public and the media amplify their voice – rather than via more official and direct channels”. Involvement with NGOs, blogging, journalism and political activity are all tools that can help researchers get their voices heard. Finally, he praised the role that universities play in convening experts and transferring knowledge to new generations.

“We’re all on this crowded world together. Our responsibility – to our children, to the poorest, and to our stewardship of life’s diversity – surely demands that we don’t leave a depleted and hazardous world”, he concluded.

The original event listing can be seen here. The lecture can also be seen on video on our online lectures page, and you can listen to the audio podcast on our Soundcloud page.