An Astrobiology Perspective on Ecosystem Services

“Biota control the basic chemical conditions on the surface of the Earth. With an atmosphere containing 21% oxygen, the chemical environment on Earth stands in start contrast to that on our sterile planetary neighbors–Mars and Venus. The metabolic activities of organisms, which link oxidation and reduction reactions, produce the relatively stable conditions on Earth that are conductive to the persistence of life.”

– William Schlesinger, Biogeochemistry 2nd Ed.

Venus, Earth and Mars

Venus, Earth and Mars

Imagine You are a Space Traveler…

Sometimes it can be helpful when framing an issue to get some perspective. When it comes to classifying the values that the vital functions that Earth’s ecosystems provide us, this perspective can be gained by zooming way way waaay out from the bird’s eye view of life on Earth to that of a space traveler who can not only see Earth, but other planets too. This interplanetary perspective falls into the academic domain of astrobiology.

As commented on by Schlesinger in the introductory quote, Earth stands in marked contrast to its sister planets, Mars and Venus. The latter two planets are both inhospitable to life as we know it, but in different ways. Venus has a runaway greenhouse effect and is too hot, and Mars has a runaway refrigerator effect and is too cold. (This is a ripe setting for an interplanetary Goldilocks tale don’t you think?)

The Critical Function of Regulating Ecosystem Services

Photosynthesis and Respiration

Photosynthesis and Respiration

One of the key factors that makes life on Earth possible is life itself. It does this by maintaining a  system of chemical metabolic  pathways. (If you want to blow your mind with the complexity of these biological pathways, download the chart from this Sigma site.) The largest source of energy driving these pathways is the sun, which provides us with an endless stream of solar radiation. The most well know, and arguably most important biological chemical processes, are respiration and photosynthesis, which–as we all learn in grade school–are essential to the functions of regulating oxygen (O2)and carbon dioxide (CO2). Life also helps to regulate other important biogeochemical pathways as well such as nitrogen, sulphur, water and phosphorus.

The simplified diagram below breaks down the central role that biota on Earth play in regulating Earth’s chemistry in such a way that it maintains relative homeostasis (similar to how our own bodies maintain our blood chemistry) over time, compared to Venus and Mars. The figure highlights the important role of CO2 in the atmosphere as well.

Venus-Earth-Mars Comparison, Nick Strobel

Venus-Earth-Mars Comparison (Image from Nick Strobel's Astronomy Notes.)

Plants and other organisms that photosynthesize create the matter (biomass) which forms the base of the food chain on Earth. Over time green plants/organisms sequester carbon dioxide from the atmosphere into their living tissues, and this is called net primary production (NPP). This photosynthetic process, along with respiration, in turn, also helps in regulating  oxygen and carbon dioxide cycles which are critical to life on Earth as we know it. Hence, the amount of food available on Earth, as well as the composition of the atmosphere is significantly regulated by the balancing act of the actions of photosynthetic organisms (autotrophs) and respiring ones (heterotrophs). Maintaining biodiversity is also important to maintaining this balance.

Humans control about 40% of the Earth’s terrestrial primary production.

How much these life processes help protect the Earth from turning into a dead planet like Mars or Venus is debatable, but what we DO know is that humans on Earth control about 40% of the total terrestrial net primary production from plants, as well as about 8% from the oceans. 40%!! This is an astounding number! And, these numbers were calculated based on data from a couple of decades ago, so the actual numbers are likely higher today.

What this means is that humans are significantly commandeering and influencing some of the vital life processes on Earth of net primary production and influencing their related chemical pathways. In some ways, we really are space travelers, and Earth is our spaceship. As our population rises on this vessel of ours, we are likely to push these numbers higher and higher over the next couple of decades.

warning lightThis brings up some key questions relating to how we are impacting the regulatory functioning of Earth’s natural systems:

  • If we think of putting a virtual green light, yellow light and red light warning system for risk to spaceship Earth’s critical life regulatory functioning, what level of human impact is acceptable (within the green range), risky (within the yellow range) and dire red alert?
  • How can we reduce the human impact on ecosystem regulatory functions that impact life support on Earth to levels that in the safe green zone?
  • Considering that we have already failed in our attempts to secure biodiversity, such as achieving the Convention on Biological Diversity 2010 targets, how will we achieve the next set of targets effectively in the face of concurrent growing human needs?

Ground Control to Major Tom, what do you think of that?


HRH Prince Charles on ES, climate change and resilience

This video is a good one for a tea break call to action.

Tea Time Talk

Prince Charles covers a lot of ground in the video below including Ecosystem Services, GDP linkages to externalities not being accounted for, forests, fisheries and aquaculture, perverse subsidies, kudos on reporting to certain groups, the history of TEEB, public private partnerships with NGO input, not leaving things to the market alone, the market-mechanism potentials that may be effective in incentivizing sustainable ends, and the role of the consumer in demanding sustainable products and services.

His final comments are the most persuasive:

“Lately I’ve been asking myself on why the public has not eagerly embraced many of the advantages in pursuing a sustainable future. My conclusion is that for too long environmentalists have concentrated on the things that we need to stop doing. If we are constantly told that means giving up all that makes life worthwhile, then it is no surprise that people refuse to change.

That is why last year I launched a new initiative called ‘Start‘ which aims to show people what they could start doing. The simple steps that we can all take to make better use of our natural resources…We are unashamedly trying to sell the benefits of sustainability…We are making it cool to use less stuff. Believe it or not, this smarter approach can actually be more profitable. As Marks and Spencer have found an innovative approach to sustainbility actually saves money.

Now I have to say this process has not exactly been helped by the corrosive effect on public opinion of those climate change skeptics who deny the vast body of scientific evidence that shows beyond any reasonable doubt that global warming has been exacerbated by human industrialized activity. Their suggestion that hundreds of scientists around the world, and those who accept their dispassionate evidence, including presumably (ladies and gentlement) myself, who rather ironically am constantly accused of being anti-science, who are somehow unconsciously biased creates the implication that many of us are somehow secretly conspiring to undermine and deliberately destroy the entire market-based capitalistic system that now dominates the world.

So I would ask, how these people are going to face their grandchildren and admit to them that they actually failed their future? That they ignored all the clear warning signs by passing them off as merely part of a cyclical process that had happened many times before and was beyond our control. That they had refused to heed the desperate cries of those last remaining traditional societies throughout the world who warned consistently of catastrophe because they could read the signs of impending disintegration in the ever more violent extreme aberrations in the normally harmonious process of nature.

So I wonder, will such people be held accountable at the end of the day for the absolute refusal to countenance a precautionary approach? For this plays, I would suggest, a most reckless game of roulette with a future inheritance of those who come after us. An inheritance, ladies and gentlemen, that will be shaped by what you decide to do here in this parliament.

Ladies and gentlemen, Mr. President, you’ve been remarkably patient at listening to me, and I promise you that what you decide here could induce the very necessary adjustments we so urgently we need to make. So can I ask if you will be courageous enough to seize the moment, set Europe on a course for survival and economic prosperity, and so earn the endless gratitude of our descendants.”