Surviving the Next Doomsday Asteroid Impact

One day, as has happened many times before, a large asteroid thousands of metres in diameter will hit our planet.

The result of the impact will rain hot debris across the entire Earth, heating the atmosphere to an oven-like temperature and shrouding it in dust clouds. Fires will burn for years adding billions of tonnes of soot to the atmosphere, and then the global temperature will fall dramatically. Photosynthesis will grind to a halt. Almost all species of plants and animals will perish. The only survivors will be those lifeforms that are able to eat the remains of long dead life, such a cockroaches and deep sea creatures.

The collision of a large asteroid thousands of metres in diameter with our planet will almost certainly result in the extinction of most lifeforms. It is unlikely that humans would survive.

If such an impact happened now humans would not survive. The extinction of our species would be certain. Essentially, life on Earth would be reset to the point just after the last massive impact event 66 million years ago (the Cretaceous-Paleogene extinction event that caused of the extinction of the dinosaurs).

By the next century we are likely to have permanently inhabited colonies on the Moon, Mars and possibly even beyond, but there will be a few hundred inhabitants at best. And most crucially those colonies will not be self-sufficient. If Earth is rendered uninhabitable and our civilisation destroyed then those colonies will die soon after. It will be a couple of centuries until self-sufficient colonies with tens of thousands (preferably millions) of people exist away from our planet. Until then we will need sanctuaries on Earth where a significant human population can survive should a massive asteroid impact occur. And by 'significant' I mean several million people at least.

The cost of building such underground sanctuaries would be extreme, and it would take decades or longer before they were ready for habitation. Hundreds of billions of dollars would be needed each year, and a workforce of millions. But it is actually affordable and achievable, if only the world's governments could be less paranoid and divert some of their defence spending to the project. The total spending each year by NATO members (29 European and North American countries) is more than one trillion dollars. If just a quarter of that budget could be redirected then the underground sanctuaries for North America and Europe could begin construction. If the likes of Russia, China, Japan and their neighbours did the same then sanctuaries in their region of the world could begin construction, too.

After a century of construction and expansion, the main chamber of a vast underground sanctuary, deep beneath mountains in Europe, is home to a thriving city of a million people. Powered by geothermal energy, the sanctuary is a self-sufficient haven for humans, one of several spread around the Earth. Even the impact of a large asteroid, such as the one that resulted in the extinction of the dinosaurs and many other species, would not lead to human extinction if such facilities exist.

Each sanctuary would need to be hundreds of metres underground, with locations beneath mountains the most preferable. As well as hundreds of kilometres of tunnels and smaller chambers there would need to be huge areas for agriculture, and even larger caverns to create the feeling of space and distance we have evolved to need, if only to maintain the sanity of individuals. Power could be generated using geothermal technology.  Energy generation using geothermal power stations currently provides 30 percent of the electricity requirements of Iceland, with the Philippines not far behind that. It is a relatively clean and renewable source of energy and would be ideal for subterranean habitats. New power generation technology, such as nuclear fusion, will hopefully be perfected over the next decades, which could provide almost unlimited power capabilities.

One of the many farming chambers that surrounds the main city of each of the underground sanctuaries. Agricultural facilities such as this, powered by geothermal energy, or even fusion energy, provide food for millions for thousands of years in the event of a catastrophic incident up on the Earth's surface.

Once created the sanctuaries would need to be permanently occupied to a high capacity: at least 50 percent. This is necessary to ensure that the sanctuaries are fully functional and under constant maintenance. They should be regularly assessed to identify areas of improvement. They would need to be totally self-sufficient if the need for them arises. There would hopefully be many months, if not years, of notice before a large impact would occur, giving plenty of time for people to migrate into the sanctuaries.

There are ethical and moral issues with regards to who would be selected to migrate into the sanctuaries should an extinction level impact be confirmed. The choice of certain sections of the population is obvious: there needs to be specialists in all areas of science and technology (engineering, medical, computing, utilities, agriculture etc) and also educators; it will be essential that education levels are maintained for the generations that will live in the sanctuaries, so schools and universities would be required.  The majority of inhabitants, however, will be ordinary citizens with ordinary levels of education and skills. Whatever method is used to choose which of those individuals and families are chosen - a lottery, or genetics (to maintain the diversity of the gene pool) - there would be objections, protests and even wars fought no matter who is chosen (there would be nations of the world without any access to sanctuaries of their own). Great care would need to be taken to ensure that the security of the sanctuaries is maintained and the chance of sabotage is kept to a minimum.

The selection of who is to migrate to the sanctuaries, and how to prevent attacks on them as they travel there, will perhaps be a more troubled process than the construction of the actual sanctuaries themselves.

Of course, it would be best if a cataclysmic asteroid collision was prevented altogether. There are numerous proposals to deflect or destroy asteroids that are identified to be on an eventual collision course with Earth. None of them has yet been tried, and all of them required many years, or even decades, of warning. Research into such methods should be intensified and an effective asteroid defence system should be implemented as soon as possible. The underground sanctuaries would allow a small percentage of our human population to survive the aftermath, but they should be considered a last resort. The need for then should ideally never arise.

Developing the ability to deflect or destroy asteroids on a collision course with Earth is essential to prevent the extinction of our species. A joint NASA and ESA mission in 2020-2021 will perform the first test of such technology.

If we construct several underground sanctuaries around the world, and deploy a system capable of destroying or deflecting asteroids, we stand an excellent chance of surviving as a species even if an object many tens of kilometres wide collides with our planet, and of eventually repopulating the surface once its ecosystem has recovered.

But, before the creation of the underground sanctuaries can happen we need to cultivate a will to change our thinking and work together for the greater good and the very preservation of our species and the wider ecosystem on which we depend. If we fail to do so we will fail all of humanity, and our extinction will be assured.

Nuclear War - Our Biggest Immediate Threat

Climate change is considered the main threat to our civilisation. Over the life time of the human generation being born right now our planet will almost certainly experience a significant detrimental effect from the amount of greenhouse gases that have been pumped into the atmosphere by our  activities. The increase in the number of forest fires in North America, flooding in Asia, and longer and more intense heatwaves in Europe is just the beginning.

It is not impossible to slow down or even halt such effects, but the huge political, economic and social changes necessary make it very unlikely that the nations of the world can come to any sustainable agreement on what to do.

As the effects of climate change intensify over the next few decades there will be severe pressure on the countries worst effected. Ultimately wars will break out as failing harvests, flooding and desertification force desperate nations to fight for the resources that other less effected nations are holding.

An artist's impression of how Miami would look with the relatively small sea level rise expected with a 1.5 - 2.0 Celcius temperature increase. It is now expected that a 3 Celcius increase is likely by the end of the century without drastic action. Such a sea level rise will displace hundreds of millions of people from coastal areas and leave major cities abandoned. Wars are inevitable.

The recent report by an Australian think-tank that civilisation is likely to end by 2050 is not at all far-fetched, but civilisation is likely to end much sooner if the political situation in many leading countries continues to radicalise. There will be little attention given to climate change by the leaders of such countries, which will be disastrous as some of them are the very ones with the ability to actually do the things necessary to limit the effects of such change. There is an ever-increasing chance of a major war between those nations. And such a war is likely to quickly escalate out of control. There could well be an exchange of nuclear weapons, which will have an immediate and devastating effect on our climate, far and above that of the climate change expected from our normal activities. Even the use of just a few low yield nuclear weapons would have a worldwide effect.

One likely scenario is between India and Pakistan: both nuclear powers. Pakistan, one of the most 'water stressed' nations on Earth, relies on water flowing from India. If India diverts that water (which it has already threatened to do in part, in response to a terrorist attack in Kashmir) and Pakistan suffers droughts then it may become desperate enough to destroy India's dams. India would retaliate. And then Pakistan, desperate and pushed to the brink as its citizens protest and riot, may feel it has no choice but to launch a nuclear attack. India will certainly respond in kind.

A long range nuclear missile launching

As well as destroying large parts of both countries and killing hundreds of thousands almost immediately, the effects of such a regional nuclear conflict would be felt across the world. Even conservative estimates predict that five million tonnes of smoke would be released into the atmosphere and trigger a nuclear winter of two to three decades, reducing global temperatures by two to four degrees and decimating the protective ozone layer (removing most of our natural protection from UV radiation). There would be widespread famine as food production is significantly reduced. Skin cancer would become common place.

Of course, the threat of a major nuclear war has been present since the 1950s, but since the end of the cold war the strict controls and mutual understanding and respect of the nations with nuclear weapons seems to have eroded. The threat of such a war breaking out is increasing day by day, and the rhetoric and threats of the major nuclear powers recently does nothing but exacerbate the situation. Russia has recently exited the INF (Intermediate Nuclear Forces) treaty following the exit of the USA a few months earlier. Nuclear arsenals are being modernised and upgraded., and a new type of missile that can travel at hypersonic speeds (greater than Mach 5) is in rapid development by Russia, China and the USA (and France recently became the first European country to announce a desire for such a weapon).

A hypersonic missile seconds after launch. It would only take it a few minutes to travel hundreds of kilometres, and it would be unstoppable with current defences. It is in development by the major world powers and is a highly destabilising weapon. 

Hypersonic missiles, against which there is currently no effective defence, can hit a target in minutes at an incredible speed. They are designed primarily to carry conventional weapons (but could carry small nuclear warheads if required), and one White House official has even dubbed them 'instant leader-killers'. This suggests one use for them: a means to assassinate the leader of a nation virtually without warning and with almost no risk of the missile being intercepted. Such an ability is incredibly destabilising.

The amount of money spent on military defence around the world is staggering. In 2018 the world's governments spent more than $1.8 trillion. The USA alone accounted for just over a third of that. We are spending about 28 times more on military hardware and development that we are on tackling climate change. To put it simply: we seem to be more concerned with securing our self-inflicted annihilation than securing our survival. Imagine what could be achieved if we could divert even just ten percent of that spending from defence to renewable energy production, for example?

One of the most chilling explanations of the Fermi Paradox (which refers to the contradiction of the lack of evidence for intelligent extra-terrestrial life when observations suggest it should be quite common) is that civilisations destroy themselves soon after developing radio or spaceflight technology (and with it the technology to wreak mass destruction). We now have that capability. It is quite likely that a nuclear war will end our technological civilisation, and the subsequent immediate climate change will almost certainly result in our near or actual extinction. And if we manage to avoid such a war, it seems that we may well be too late in trying to tackle the climate change that is happening now.

As I've discussed before, our survival instinct, which has served us well up until now, continues to ensure that we will develop more and more powerful weapons to defend ourselves, and allow us to forcefully take what we need to survive. Ironically this instinct now seems to be taking us closer to extinction. Our natural instinct to be suspicious of others seems almost impossible to overcome. We are unlikely as nations, and even as individuals, to cooperate enough, and to put aside our differences, to work together and sacrifice some of our comforts in order to stop climate change or the risk of a nuclear war.

If we can survive the next few decades, and work together instead of feeling the need to build ever more destructive weapons with which to destroy each other, our civilisation will be well on the way to expanding beyond Earth and creating colonies on and around other planets. Pictured here is the impressively conceived Venus cloud colony.

If it's true that almost all the intelligent civilisations in our galaxy destroyed themselves soon after they developed the ability to do so, then it is likely that we will too if there is not a radical change in our behaviour. We must strive to be one of the exceptions. We need to grow beyond our blind sprint towards our own destruction. It is the only way we can avoid an eventual nuclear war. And it is the only way we can tackle climate change and save our planet. If, against all odds, we manage that then we will be well on the way to expanding our civilisation beyond the Earth. Our long term survival as a species will then be assured, and we will take our place among the select few civilisations that overcame their self-destructive tendencies.

There is still time. There is still hope. But both are dwindling fast.