The Science

All right. Where to start. Science… Or rather The Science:

That continuous and unceasingly self-critical enterprise of clever, talented, hard-working & knowledgeable others – others to whom we owe so much – that serves as the foundation for our own little enterprise and for that of so many who try their bests to maintain the beauty of our planet and ensure Earth’s continued liveability.

We don’t really know where to start about that science – so perhaps this is a good spot to sneak in some promotion for our very own science news coverage. If you’re interested, please take a look at: – we’re secretly quite proud of it…

Definition of science. Well, one of them.

Now let’s try to be honest…

We Love Earth is mostly about what we think is beautiful, and what is dear to us. This page might be a bit different though. This is where we will tell you what we are concerned about, and what we want to prevent.

That means we will talk about a couple of things that are not going so well. We really love the diversity of Life on Earth, so if there is one thing we really dislike that is biodiversity decline – the die-off of life, that colourful bouquet of unique species, at a rate far, far higher than the background pace of natural evolution. That biodiversity decline we think is degrading to our planet – and especially to us, the species causing it.

So here on our special science page we must acknowledge realities of overfishing, deforestation and other major factors leading to that biodiversity decline, most notably climate change. We might even mention that nasty and unwanted Holocene Mass Extinction – a term we notice so many people in the environmental movement seem to shy away from, alarmism is bad for public relations, your marketing colleagues may have convinced you.

We actually have a different conviction: Truth Sells. As long as you try to – always – stick to it. Trying just that is the very endeavour of science.

So let’s get to it.

Earth’s atoms play a very special dance

As we don’t really know where to start, here’s just a handful of things that science has taught us:

It looks flat but it isn’t. (We never found definite proof ourselves, but everyone says we’re dumb to disagree, so we won’t. Something with an emperor and a new set of clothes.) The Earth is a sphere – a planet – floating through extreme expanses of nothingness. Although we clearly have company of other celestial objects – fortunately including a nice and sunny Sun and for dramatic night time effects a well-proportioned Moon – research by clever people has shown our planet is in fact really rather unique, at least in our part of the universe, as on our planet atoms play a very special dance – played abundantly even – throughout our oceans, across the land, and even in the skies:


Science tells us much more. While our probes and telescopes have counted zero on the Moon, zero on Mars, zero on Venus or on any other planet that has come under the attention of scientists – lifeforms on Earth turn out to be practically uncountable – we share the cradle of Earth’s evolution with that many others.

(Of course ‘uncountable’ is indeed a bit unscientific and also not true. If you want a number to get a grasp there is one: From science we learn the human species is just 1 in over 10 million species on planet Earth. We personally feel that is a humbling ratio.)

Nothing is more valuable than biodiversity. (That should be by definition!)

All these species combined define terrestrial biodiversity. And if you were to state that nothing is of greater value than Life, then it is this biodiversity, more than any other resource or riches, that is, by definition, the most valuable thing we have, on Earth.

Common biodiversity definition. Bit dry for our liking...

This biodiversity though is rapidly declining, as a result of synergistic human-induced stress factors. These stress factors range from local pollution, overfishing, deforestation and other habitat destruction, increasing monoculture land use, to ecologically disturbing grand-scale processes like the chemical alternation of our entire ocean-atmosphere system with extreme amounts of carbon, leading to ocean acidification and increased heat absorption, which in turn leads to further disruption of Earth’s climate system and the natural carbon cycle.

Scientists speak of the Holocene Mass Extinction, the sixth mass extinction (in which at least 75% of major lifeforms will die out) in the 4.5-billion year history of Earth, which might already take place within our current century.

Yet most people are not even aware this is in fact the largest and most structural change that is occurring in our shared physical world, the change that marks the end of our current geological epoch, the Holocene – and possibly even the end of our current geological period, the Quaternary – to start a new era with the onset of the Anthropocene, the human-induced dent in the Earth’s fossil record.

Early bumblebee (Bombus pratorum), buff-tailed bumblebee (Bombus Terrestris) and white-tailed bumblebee (Bombus lucorum) on sunflower.

Experiencing biodiversity is very much about keeping your eyes open. Then you can for instance spot three different European bumblebees on this sunflower. And yes, of course science gave each of them proper names. Left to right: Early bumblebee (Bombus pratorum), buff-tailed bumblebee (Bombus Terrestris) and white-tailed bumblebee (Bombus lucorum) on sunflower. These are still quite ordinary bumblebees, but let’s ask ourselves how many of them would survive the pending Holocene Mass Extinction. Quite possibly none of them. Think about it. We really need to change.

Our unawareness of the pending Holocene Mass Extinction that we cause lets aside if we care about it – that is if we do or do not realise that having a mass extinction is simply the worst thing that could happen – to us all, the most degrading thing to our planet, and the most damaging thing to what we should all agree we cherish most: Life.

(Preventing) the Holocene Mass Extinction

So how do we prevent this cascading decline of life? How do we prevent the mass extinction?

Perhaps firstly we will need to, collectively, revalue biodiversity(?) That is, we will need to become aware – fully aware – of the value of biodiversity, to understand why we should not, why we do not want to lose it – to lose it at speeds that evolution cannot compensate for.

To achieve this we will have to re-establish a healthy connection of our species to our natural world. We will need to show each other – to take that time, together – just how special each and every little bumblebee actually is – if only you take the time to appreciate, if you try to investigate its little wonders, the endless wonders of Life on Earth.

Then of course we will need to get practical. To prevent extinctions and general biodiversity decline major drivers of that biodiversity decline must be tackled, effectively, on a global scale. We will need to protect our oceans (firstly from overfishing) and, in order to stop deforestation and other natural land degradation, lower our human net general (agricultural) claim on land. That means (while the human population is forecast to continue to grow by billions) we will need to get (much) more efficient and less ecologically destructive in our food production. Most likely we will have to transition away from animal protein sources to a human diet that is supplemented with a wide range of far better sustainable plant protein sources – some of which might even need to be derived from agricultural waste streams.

But apart from looking at the way we treat our Earth’s oceans and land masses, we might need to perhaps pay even more attention to our Earth’s atmosphere.

That is because in this century climate change is set to become the largest of the major extinction drivers – amplifying and far exceeding the impacts of overfishing, deforestation and other forms of pollution.

Why Climate Change is So Bad – 1: Ecology

Of all individual stress factors climate change is likely to become the largest driver of biodiversity decline (as clearly illustrated in the linked Nature study above).

But why? Perhaps to many it isn’t all that clear-cut that climate change – essentially ‘having a somewhat warmer atmosphere’ – can have such extreme ecological effects. But it’s true – and from our understanding of science (feel free to disagree), it is climate-induced biodiversity decline that should worry us much more than say… freak storms, sea level rise, or even drought – the stuff you hear most about in the climate news – impacts that (by the way they are formulated) place us, humans, central – and forget that we too are fully dependent on Earth’s connected ecosystem…

The main mechanism, if you’re interested in the detail, is basically as follows. Specific trees cannot live without specific ants, which cannot live without specific fungi, which cannot live without specific soil acidity, which depends on the presence of yet different trees – or rain, or insects, or other fungi – or, yes, why not, a butterfly! And each and every butterfly always, is (almost) entirely dependent on one specific type of flower, in biology called the ‘host’. If that one flower isn’t there, the butterfly population will die out. And when the butterflies die out, where are the caterpillars that the song birds wanted to feed to their youngs in springtime?

This is what an ecosystem really is. Connected. Dependent. It can survive a small shake. But when you stress it, stress it too far, and stress it too long – it can start to (really quite suddenly) disintegrate, and collapse.

Ecological tipping point Earth

Ecological tipping point Earth, well-illustrated in this Berkeley study in Nature. When stress factors keep increasing, a ‘sudden’ collapse follows.

Now how does climate come into this equation? Everywhere across the globe we find ecosystems, and all of these are interconnected. But on every spot, over millions of years of relative stability (tropics) – or at least many thousands of years of stability (higher latitudes) – we find that all these species have come to evolve and come to form their dependencies, their ecosystems, founded on the basics: The hardcore physical world (soil, rock, mountains, rivers, coast) – and the heat, amount of rain, sun exposure – the local climate.

Of course all these local climates are also connected – as the Earth’s climate system. And to that system, our CO2-induced climate change essentially means one thing: more energy. More energy in that climate system, means its morphology will become an exaggerated form of itself. The general circulation will speed up. More rain in the already wet tropics, less rain in the already dry subtropics. And so on.

2D general circulation in Earth's climate system

If you want our best piece about ‘the general circulation’ of Earth’s climate system, click on the image above. It is ‘officially’ about the influence of El Niño on Atlantic hurricanes, but we think that is a very good case to better comprehend this is in fact a 3D system. Climate change is likely to lead to a weaker Polar Cell and a stronger – and therefore also bigger – Hadley Cell. Tropical rainstorms will grow higher, while zones of desertification will grow larger, towards higher latitudes, consuming for instance the Mediterranean. But the story could only be that simple on a featureless sphere – not on planet Earth.

Having wetter tropics and drier subtropics may be damaging enough – but the Earth isn’t that simple and straightforward. Parts of the general circulation may meander, while others stay in place. At places the monsoon can be drawn far away from the equater to bring torrential rains where no one expects them (see picture below) – while in other places, like over the Indian subcontinent, the opposite happens, and the monsoon is blocked. In North Africa the picture is skewed, with likely desertification in the western and central Sahel – and increased rainfall and flooding risk in the eastern Sahel.

Rain in the desert - Cyclone Chapala, Oman

In 2015 Cyclone Chapala brought 4 years of rain in one day, for Yemen and Oman. It wasn’t ‘supposed’ to be there – especially since it wasn’t the only tropical storm product that got so far of course in that year, to bring unseen rains in that desert. Meanwhile much of the Middle East becomes drier, fast – with desertification to include once fertile lands of northern Syria and Iraq.

Probably the most dramatic example of the capricious changes in Earth’s general circulation does not come from Africa or Asia though, but from Latin America – the possible disappearance of an entire wet zone: The Amazon – due to a drawn away monsoon and disturbance of the daily rain cycle, leading to a self-accelerating seasonal drought and forest fires feedback. Sadly we’re also talking about a crucial carbon store (~70Gt in biomass) and Earth’s largest terrestrial biodiversity hotspot…

The Amazon drought-fire-emissions climate feedback

The Amazon drought-fire-emissions climate feedback. One of the best examples of how things can go really wrong, in practice.

To sum up the above, what we are essentially trying to describe here, is the word chaos

Ecology does not like chaos. Ecology likes stability.

…the Speed of the Change is the Problem…

When favoured climatic conditions around which they evolved change, species try to migrate. The problem here is speed of change. A bird can fly the length of a continent in a couple of days. For a tree that might take thousands of years, and is very often impossible. Entire ecosystems would have to slowly creep to keep up with the warming trend. (1 degree warming means the core of your climatic zone migrates by about 200 kilometers towards the poles (depending on geographical location) – many trees would have to walk 4 kilometers per year to keep up!) For an ecosystem as a whole such migrations are only possible when changes happen really, really slowly (tens of thousands of years, not a century) – and preferably are limited in scale.

Ecological climate migrations are already happening, on land, in the air – and, perhaps surprisingly, the challenges of finding new habitat are equally challenging for marine life.

Today’s world is stressed already – in very many ways. Large, complex, interconnected migrations of species will fail – that is where climate change leads to extinctions.

To understand why climate change causes biodiversity decline, try to zoom in to this level...

Giant water bugs, typically living in freshwater streams and with a size up to 12 centimeters among the largest of the insects. To smaller insects they are dangerous hunters. But there’s also something sweet to tell. See the water bug on the picture. Those are eggs and he’s the father – who carries them around and protects them from the cold all winter. Here as an example of a vulnerable microscale ecosystem.

When we look not at single species, but at ecosystems, scientists can predict collapse under climate stress at any scale level – from a single freshwater stream, to a medium-sized forest ecosystem like Yellowstone – to entire shifts in the global biomes distribution, many of which will ‘flip states’ according to NASA research…

Climate change leads to biomes shifts, therefore ecosystem collapse

Why Climate Change is So Bad – 2: Physical Underestimation

All right. We’ve seen how climate change can be bad for ecology. But we’re only close to 1 degree of global average warming right? It can’t be that urgent yet, is it? Don’t we have time?


We don’t have time, anymore. Here is where we try to explain why – using 1 single study that was published (ten years ago) by a very well-known climatologist in a very well-known journal, and that should shake all our worlds:

One of the most important reasons why the urgency and the likely scale of damage of climate change is still so easily underestimated lies in the so-called thermal inertia of the climate system: Due to heat absorption in the Earth’s enormous ice and water masses (to be exact about it, top to bottom the Earth’s oceans weigh about 250 times as much as the atmosphere) a delay has risen between the graph of emissions and the graph of the atmospheric warming that is caused by the extra atmospheric heat absorbtion that these emissions cause.

The best Science is of course published in Science and there this climate emissions-warming delay is estimated (by James Hansen, the world’s most reveared climate scientist) to be somewhere around 37.5 years.

This means we do not witness direct climate impact of our emissions. Rather the warming currently witnessed [which by the way is already resulting in halving of Arctic sea ice volume – just to get a sense of impact scale!] is the result of global cumulative CO2 emissions up to the late seventies, emissions which have doubled since.


IPCC historic emissions graph

Historic emissions graph of the latest IPCC report (2014). CO2 works cumulative in the atmosphere, but due to thermal inertia of the climate system, we don’t yet witness warming caused by CO2 emissions beyond the late seventies – emissions which have doubled since. This is climate change that is already in the pipeline – inevitable climate change, even if we fully stopped emitting per tomorrow, globally.

This also means warming is inevitable to almost double (or at least rise by an additional 0.6 degrees Celsius after fossil carbon emission return to zero – Hansen) and is likely to surpass doubling since all established emission scenarios show the global economy is planning to continue the emitting habit. [These ‘established emission scenarios’ can therefore not be accepted – to stay close to the agreed safe margins the world will simply have to stop burning fossil fuels, much sooner!]


IPCC future emissions scenarios

Future greenhouse gas emissions scenarios according to the latest IPCC report (2014.) None of these scenarios are ambitious enough to have a reasonable chance to stay within agreed safe margins. The world simply needs to stop using fossil fuels – sooner than anyone can imagine.

It is also important to realise that the damage of climate change (which applies to all ecological stress factors) increases exponentially with warming, so 2 degrees causes more than twice as much damage as 1 degree of global average warming – and so on to 3 degrees, 4 degrees, and beyond…

So where should we be aiming for? Well – as with ecological consequences, as with inevitability of much of the change, also with the physical impacts it causes, people generally tend to dramatically underestimate the severity of climate change – especially if you would be concerned not about your own well-being, but about that of our children.

We are currently setting into place a change that will continue to show increasing effects long after we are gone.

To get back to the numbers. You often hear of 2 degrees – as ‘a target’. Well, why don’t we take a look at what the science tells us about 2 degrees. Just one example, of one consequence, for Earth, if we were to have a new climatic equilibrium that is 2 degrees warmer than the climate humans evolved in.

That 2 degree warming will not equate to some 50 or 80 centimeters of sea level rise, as our politicians would want you to believe, but to something in the order of 12 to 32 meters*, if you’d use paleoclimatological comparisons.

(And yes, such dramatic numbers make sense in the modern world of computer models too. Just do the math yourself. At +2 degrees you first have several meters of thermal expansion. Add to that complete melting of the Greenland Ice Sheet and (probably) also of the West Antarctic Ice Sheet and you’re definitely in that range above 12 meters. It won’t happen fast. But it will happen. And will become irreversible once it gets going. Again, just 2 degrees.)

Climate change: 2 degrees warming = 12-32 meters sea level rise

Credit: Olafur Eliasson and Minik Rosing, Ice Watch, COP21 climate summit, Place du Panthéon, Paris, December 2015

And that is just what sea level rise does. Three degrees and the Amazon will be largely gone – just one indication of the larger Holocene Mass Extinction that we spoke of earlier in this piece. Having a mass extinction is No Light Matter – because once things start to collapse, no one can predict where the cascading decline will come to a halt – if at all it will. Again paleo science comparisons are most useful here.

Once the larger species die out, human survival too is no certainty. A single plague can kill a planet. Please read it.

We think this sobering article is coming to a close. But before that we need to look at the numbers once more. All we can say is that 3 degrees just like 2 degrees are in the end unacceptable numbers ‘to aim for’. That is why we think the one good thing that happened during the COP21 climate summit in Paris in December 2015 was talk – talk, sadly nothing more than just talk, no policy, no targets, no obligations to act – of a new, more ambitious climate target, that is at least an improvement: 1.5 degrees.

#1point5 = LifeLine! Our banner during the Red Lines action on D12, COP21 Paris

But let’s remain realistic. Those same politicians could not agree on binding emissions targets. And if all those targets (2030 emission reduction targets) would have been made binding, and would in fact be implemented, that would still only bring the world on a pathway towards 3.5 degrees warming.

But the scientific reality of Earth is worse than that strange parallel universe of the policy-drawers around the UNFCCC.

Because for some bizar reason there is one piece of science that all of these policy makers just simply refuse to acknowledge up to this date – and that is hard and true science of positive feedbacks in the climate system.

Arctic tundra methane, taiga CO2, deep sea methane, tropical forest CO2, ocean acidification CO2, ocean warming CO2, soil degradation CO2 – no one knows, really no one, the exact scale of the many suggested positive feedbacks that act on Earth’s carbon cycle, when warming hits them – but there is one thing we know for sure. Most of these processes act in one direction: they amplify the disruption, once a tipping point is passed.

And that is – again – because we live in an ecosystem. One big ecosystem called Earth.

The taiga forest climate feedback. There is some 700 billion tonnes of carbon stored in this biome...

The taiga. Or boreal forests. Earth’s largest terrestrial carbon store – and threatened by climate change (drought, forest fires, plagues, soil degradation). There is an estimated 700 billion tonnes of carbon stored in this biome. Taking into account such positive (carbon) feedbacks science shows that climatic warming of over 6 degrees within this century is still very well possible – against a background of political talk about 1.5 degrees [a target we strongly support – see our picture!] during COP21, the UNFCCC climate summit in Paris of December 2015.

The currently witnessed climate change offers only a sneak peek of likely climate-induced damage within this century. Much of this damage is unacceptable if we want to maintain a habitable planet and prevent the Holocene Mass Extinction.

Much of the looming climate catastrophe can indeed still be prevented. That is only possible if we hold politicians and nations to their word and consolidate the new international climate target, of limiting warming to no more than 1.5 degrees.

That challenge is as simple as it is ambitious. Earth will have to become 100% fossil free before the first half of this century is through. And meanwhile we have an almost equally important food transition to work on.

Let’s do it.


The 'hierarchy' of sciences,

A hierarchy of science(s), expressed in their relation to the scale of the physical universe. Based on Richard P. Feynman (‘The Great Explainer’) | The Feynman Lectures on Physics (1961-1963) | Image credit: Eric Fisk, 2013, Creative Commons Efbrazil.