Climate Change - The Point of No Return

We are on the verge of rendering our planet uninhabitable, unless drastic action is taken.

Scientists have recently announced, quite alarmingly, that climate change on our planet could soon reach its tipping point. We are only decades away from that moment. It will happen within a generation.

Lowering our carbon dioxide emissions is no longer enough. Carbon dioxide needs to be extracted from the atmosphere. And we need to start doing that now on a large scale. Otherwise, global warming will enter an unstoppable feedback stage, where warming triggers more warming, which triggers even more warming. Such feedbacks include the release of methane due to the thawing of permafrost, loss of snow cover, the melting of Arctic ice, warming seas, and the loss of forests. All of those will reduce our planet's ability to reflect heat and absorb carbon. The number and intensity of forest fires will increase dramatically, releasing huge amounts of greenhouse gases into the atmosphere. This will only magnify the feedback effect even more.

Global warming will result in an increase in the frequency and ferocity of forest fires. Such fires add vast amounts of greenhouse gases to the atmosphere.

The end result of such warming is not clear, but at best it will significantly limit the areas of the Earth where humans can comfortably survive. At worst it will render the whole planet uninhabitable, water will boil away, and the Earth will suffer the same fate as Venus,

Even the 'best case' scenario will cause massive migrations, and subsequently major wars over dwindling food, water and energy resources. Such wars will only add to the warming feedback. As the desperation of governments increases those with nuclear weapons at their dosposal will eventually use them. Countries such as Israel, India, Pakistan and Iran - all nuclear powers and all located in what will become some of the worst affected regions - will feel compelled to use such weapons as countries to their north attempt to stop the migration of their populations. This will cause tremendous damage to the environment, and render even more areas uninhabitable. And there would be a very high chance that a limited nuclear war would escalate rapidly into a global nuclear conflict.

At that point our current technological civilisation will end, and with it humanity's chances of spreading beyond the Earth to become an interplanetary, and then an interstellar, civilisation. Our ability to preserve our species will have slipped away.

If he climate change wars turn into nuclear conficts they will bring to an end our current technological civilisation. Humans may have a change to develop another advanced civilisation one day, but it is likely to take centuries or even millenia to get back to anything like that which we have achieved today. Without forewarning such a civisation is almost certainly doomed to suffer the same fate as the one before it.

Such a dramatic warming of the atmosphere will cause a rapid rise in sea level, raising it to well over a hundred metres higher than it is at present. In addition to the billions who had already perished in the wars of the previous decades, hundreds of millions more will die. Survivors, who will eventually number just a few tens of million at best, will struggle to live in the few remaining higher altitude lands. Their existence will be basic and medieval. It will be a return to the dark ages. Thousands of years of progress and knowledge will have been lost.

Only then, with the destructive output of our current civilisation at an end, can the climate of Earth have a chance to stabilise. The ice caps will reform and the sea level will reduce. After many centuries flora and fauna will start to recover. Only at that point, humans, if they are not extinct, will have another chance at building a technologically advanced civilisation.

It's unlikely that we can prevent a climate change disaster on our planet, but we can improve on the 'best case' scenario if we start doing three things right now:

1. Preserve Knowledge of our Discoveries and Inventions

We must help survivors in the post-climate change world avoid repeating our calamitous mistakes, and allow them to 'fast-track' through what has taken our current civilisation thousands of years to learn, discover and invent.

A comprehensive record of our achievements (and of our destructive actions, so that mistakes are not repeated), must be preserved in a way that they can understand, and in a way that will last for thousands, even millions, of years. We must investigate how we can provide such knowledge to our distant descendants, and then store it in multiple safe yet easily accessible locations, including locations elsewhere in the Solar-System.

DNA could be the ideal solution to extremely long term information storage

Using paper or digital media to preserve knowledge will only be suitable for a few hundred years or so, but such means should be used initially, as our descendants will be able to understand and use these forms of storage.

But a more radical solution is needed for complex and advanced knowledge that will be useful once any new civilisation progresses to a certain level. Storing information in DNA is one such solution. It's been shown that if the DNA can be kept at sub-zero temperatures the information will maintain its integrity almost indefinitely. DNA information stores would be best located away from Earth, perhaps on the Moon in the permanent darkness of one of the polar craters, and deep within some of the planetary bodies of the outer Solar-System.

2. Work to Avoid or Delay the Climate Change Tipping Point

Even to just delay the tipping point we need to start work now.  The small steps some of us are currently taking are utterly inadequate.

Our civilisation needs to fast track the very widespread use of electric vehicles by banning petrol and diesel engines within a decade. All developed countries need to push this idea hard, and give incentives to developing countries to do the same. And governments need to increase vastly the funding for research into clean energy, and get nuclear fusion working. The generation of electricity by burning coal and oil has to stop on a worldwide scale without delay. Countries like China appear to be increasing the use of fossil fuels for energy generation, which is going to be catastrophic if it is not prevented.

But that alone will not be enough. We need to start undoing the damage we've already done.

Various climate engineering projects should be started immediately. These are possible with current technology. To help reduce global warming solar radiation management needs to be implemented to reduce the sunlight absorbed by the atmosphere. Relatively simple things can be done such as seeding clouds with sea water to brighten them (and therefore reflect more sunlight), and using pale roof colourings and promoting the expansion of polar ice.

Removing carbon dioxide from the atmosphere using facilities such as this is possible. It can be stored in hard pellets which can be buried deep underground.

We need to start removing some of the excess greenhouse gases that our activities have pumped into the atmosphere. This can be done directly using machinery that would then store the extracted carbon dioxide deep underground, and indirectly by promoting natural processes, such as extensive tree planting to reverse deforestation, and ocean fertilisation to add nutrients to the upper oceans to increase carbon dioxide absorption.

And the growth of our human population needs to be controlled, especially in developing countries. We can no longer support such large increases, which are generally located in regions that can least support it. It should be stabilised as soon as possible, and allowed to reduce naturally to a more sustainable level.

Doing all of the above is the best chance the Earth has of remaining a viable place for humans to live. But it is likely to only buy us some time - nothing more. We need to establish our civilisation elsewhere to properly secure our future.

3. Secure the Survival of Our Civilisation Independent of Earth

There's a significant possibility that the feedback warming will not stop, and if that is the case the Earth could indeed end up in a state similar to that of Venus.

The only way to ensure the continuation of our species beyond that event is to make sure that there are self-sustaining human colonies beyond Earth, on planetary bodies such as the Moon, Mars, and especially on what is looking like the best location: Titan, the largest moon of Saturn.

As well as colonies on planetary bodies there should be very large space habitats constructed throughout the Solar-System that would house tens of thousands. The resources to build such massive facilities can be found in the asteroid belt between Mars and Jupiter.

We will have to mine asteroids on a large scale to construct the off-world facilities humans will need to live independently from Earth

Extracting those resources would be relatively easy due to the very low gravity wells of the asteroids. The establishment of mining operations there must be an immediate priority. The space habitats could be constructed in the asteroid belt and then maneuvered into their final positions, either into planetary orbits, or into their own independent orbits around the sun.

In parallel to the development of colonies around the Solar-System there needs to be development of interstellar missions with the goal of establishing human colonies around other stars. More and more exo-planets with the potential for colonisation are being discovered all the time, with one, Proxima Centauri B, only 4.3 light years away.

The planet Proxima B, which orbits Proxima Centauri 4.3 light-years from Earth. It's the closest known Earth-like exo-planet, and has huge potential as a suitable destination for our first interstellar colonisation mission.

It would be a mammoth undertaking, and there are incredible engineering challenges to overcome, but investment in the rapid development of the methods and technology required is essential to build such habitats in time. As well as providing immediate funding, it should be the priority of governments to ensure that education systems are geared to maintain a constant supply of highly capable scientists and engineers to make it a success. The long term survival of our species depends on it.

If all three of the above steps - preservation of our knowledge, delaying or avoiding the tipping point, and establishing large self-sustaining human colonies elsewhere in the Solar-System and beyond - are pursued with the resilience, determination and creativity that our species has in abundance, then we will survive.

But we must start now.

Right now.

Modifying Humans For Life in Space

Does life need an atmosphere like Earth's?

Not always, it seems. Simple life can survive in the harshest of conditions. Can humans be engineered to survive in such conditions too? To find out we need to understand how simple life-forms manage it, and consider any existing evidence of life surviving in space.

Panspermia is the theory that life is spread through the universe by debris thrown into space by violent impacts. Some of that debris, containing hardy microbes similar perhaps to Earth's extremophiles, eventually lands on a suitable planet, and evolution begins. This theory becomes highly plausible when we consider that there are some Earth microbes that can indeed survive in the harsh environment of space. It seems that life that can survive a long exposure to deep space may well be extremely common.

Chroococcidiopsis: an extremophile with the potential to help terraform Mars

But could complex, and even intelligent, life be engineered to survive in the extreme conditions of space?

It certainly seems possible, and there is a complex creature on Earth that can survive in space, at least for while: Tardigrades. These tiny animals are found everywhere, from mountain tops to the depths of the oceans, and from the tropics to the Antarctic, and are the toughest multicellular organisms known. They have remarkable survival abilities. The can withstand temperatures from -272 Celsius to 150 Celsius, pressure up to six times that of the deepest oceans, exposure to radiation hundreds of times higher than the lethal dose for humans, and they can be frozen for decades and still live on and reproduce after thawing.

And they can survive in the vacuum of space, the only know animal with that ability.

A Tardigrade, the toughest known animal. It is almost impossible to kill.

Why did such a resilient creature evolve on our planet? Could it be used to engineer a more complex and possibly intelligent lifeform, or even to modify humans, to live in extreme environments?

I think so.

Alongside all the usual research that will enable humans to embark on interstellar colonisation (new propulsion systems, generation ship design, closed life support mechanisms etc.) research into how humans could be re-engineered to survive in harsher environments is also essential.

Perhaps on a generation ship there could be a genetically modified element to the crew that could look after the 'standard' humans that are forced to remain in their rotating Earth-like bubble at the centre of the ship. The modified crew would be able to survive for long periods in minimal gravity, and with a limited atmosphere. They would look after the ship and ensure that the standard humans are in good shape to land at the destination world. They would breed as the standard humans would, replenishing their numbers as the centuries of the voyage rolled by.

The genetic engineering could even extend beyond just the physical and tune psychology and intelligence to match the intended function of the modified human, rendering them almost perfectly adapted to their roles.

All of this would ideally be monitored and controlled by an immortal crew, another set of engineered humans that would oversee the whole voyage, and ensure the continuation of the thought and culture of the standard humans whose descendants would one day colonise the destination planet (see my earlier article 'Immortal Travellers').

As well as the scientific challenges to modifying humans in such a way, there are ethical challenges too. And the ethical challenges may end up becoming the hardest to overcome. But such challenges must be faced and surmounted if we are to have the greatest chance of surviving long enough to spread our species out amongst the stars.

Experimenting on human embryos and allowing them to grow to maturity to see the effects of genetic modification would be unacceptable, and also very time-consuming. Instead, sophisticated computer simulations need to be developed to give genetic scientists the ability to design such humans, and test them in virtual environments. Only when we are sure we have developed a new breed of human perfectly adapted, both physically and mentally, to the desired environment, should actual living versions be grown.

Computer programming languages already exist that can be used to add new 'features' to DNA. Such languages are in the early stages of development and use, but in the near future, when such languages are used in conjuction with a virtual simulations of the results, we will have the ability to design a perfectly adapted crew for deep space travel. With the constant improvements in computing power the systems required for this, and the software to run on them, such facilities may well be available in just a few decades.

A neanderthal family

Forty-thousand years ago there were four species of humans on Earth. For almost the Last 20,000 years our species, homo sapiens, has been the only one.

Perhaps that is about to change?