Over the past 20 years, Earth Overshoot Day—which marks the date by which human population exhausts nature’s budget for every year—has moved up three months to 29 July, the earliest ever, according to the international research and sustainability organization Global Footprint Network. As an official statement explains, this means that humanity is “currently using nature 1.75 times faster than our planet’s ecosystems can regenerate, equivalent to 1.75 Earths."
These continued massive hits on the planet’s future regenerative capacity have made the search for life on other planets and solar systems all the more vital in recent years. Lewis Dartnell, professor of science communication at the University of Westminster, researches in the field of astrobiology—which studies the origins, evolution, and future of life in the universe. The London-based author and research scientist, who was recently in India as part of British Council’s GREAT Talks series, believes the very tools humans designed to extract resources from the Earth are now damaging the planet. The numbers back it up: “the Global Footprint Network says carbon emissions from burning fossil fuel alone comprise 60% of humanity’s ecological footprint". Dartnell explains over the phone, “We are extracting our natural resources too quickly and they are not being replenished. We are not recycling enough," explains Dartnell.
The astrobiologist talks about the search for life beyond the moon and Mars, how small, individual decisions could have a big say in the Earth’s future, and the significance of India’s ‘Chandrayaan-2’ mission for further space exploration. Edited excerpts:
How significant is astrobiology as a field of science?
Astrobiology is very interdisciplinary. It involves biology as well as chemistry, geology, earth sciences and planetary sciences. There are many different opportunities for science to get involved in this search for life beyond the earth. I think the discoveries that it promises, or is trying to accomplish, can be deeply profound. If you find life on Mars, for example, that would be a hugely significant scientific discovery, one of the most important discoveries in human history.
How interesting is ‘Chandrayaan-2’ for you, given that it will be conducting experiments near the moon’s south polar region?
India’s Chandrayaan-2 mission is phenomenally exciting. No one has landed near the south pole or the lunar pole, so that will be a first-ever that India achieves. So, it’s technologically very exciting as a mission as we explore space, but also scientifically it promises very exciting results because it will be looking for water ice in permanently shadowed, cold craters by the south pole. That ice will be very important in supporting human missions to the south pole and supporting a moon base with astronauts. They will be able to melt that lunar water (ice) and drink it, and also split the H2O to get oxygen, which they can then breathe.
After the moon and Mars, what do you think is the next big frontier in not only the search for extra-terrestrial life, but for habitable planets beyond earth?
Within astrobiology we are very interested in Mars as our next-door neighbour planet, but also other places in the solar system. So, Europa is one of the moons of Jupiter and we think Europa also offers a habitable environment and conditions suitable for life.... So that is one of the targets in the solar system that we are keen to look at, while with our robots, space probes and using our telescopes, we are hoping to discover more and more earth-like planets in our galaxy. Astrobiology has come a long way. In the last 15-20 years, we have made some very important discoveries about life on earth. There’s a lot still which we are trying to explore now.
Your latest book ‘Origins: How The Earth Made Us’ looks at our planet’s geological history. How interesting a case study is the Indian subcontinent, given its varied mineral deposits and rich fossil record, in learning more about the evolution of the Earth?
With Origins, the one chapter at the beginning is about human evolution, but 90% of the book is about history and how the Earth has influenced the development of our civilization and our society.... I talk a lot about India in Origins. I talk about how India created the Himalayas by contact or collision of India moving north to Eurasia and colliding.... The Himalayas have been hugely influential in determining the climate of the entire earth over the last few tens of billions of years. There’s a chapter about the monsoon winds—across the whole of the Indian Ocean and how that determined a great deal of trade and communication, exchange of ideas across Eurasia by sailing ships—and about how the wind created by fundamental processes on the Earth have enabled humans to move around the planet and exchange ideas, knowledge and technology with each other. I also talk about the Deccan Traps and how a huge volcanic province that erupted, in a particular chapter (in the book) on earth’s history.
A recent Global Footprint Network report says that by July-end, mankind had already used up its allowance of natural resources for 2019? What is your reaction to that?
I am familiar with those studies. In essence, the story of humanity is a story of us getting better and better at making tools and extracting what we need to support ourselves from the local environment. That has progressed through hundreds and thousands of years of our history. But we are now creating a problem for ourselves and for the entire planet because our tools and our technology have become too powerful and influential. Our population has grown to cover the whole world... It’s not just a problem with climate change and global warming but many different problems that arrive, I also believe, from humans exerting too much influence on the planet with technology.
How vital is it for every individual to calculate their ecological footprint?
We can’t, as individuals, be lazy and then rest on our laurels waiting for national governments to start making big policy decisions about recycling or using more renewable energy, or controlling pollution or overuse of natural resources. We have to make individual decisions, each of us, about our own lifestyle because a lot of little contributions all add up very quickly. Each of us have the responsibility to look at our own lifestyle and try to be more sufficient with the energy, the resources we use and the impact we have on the planet in terms of how often we fly or where our food comes from.
