Two JRC scientists discuss their contribution to the Living Planet Report 2018 published today by the World Wildlife Fund (WWF).
The WWF's Living Planet Report is a science-based assessment of the health of our planet. It has been tracking the state of global biodiversity since 1998.
JRC scientists Arwyn Jones, Alberto Orgiazzi, Alan Belward, Jean-François Pekel, Andrew Cottam and Luca De Felice contributed to the 2018 edition of the report.
We had a chance to talk to Alberto and Alan about their contributions, their views on the state of global biodiversity today, and how science can help direct us in the right direction.
Q: Alberto, your chapter of the report is entitled What's so special in the soil? Why did you choose this title?
Alberto: "We chose this title because as soil scientists, we know that people often do not consider soil as anything special. It's just dirt in your garden. We also know that soil protection is not a high priority on many political agendas.
But it should be. All life on the planet depends on soil. Without soil, we wouldn't be able to grow food. In fact, it has been estimated that approximately 98% of all our daily calories come from the soil.
And apart from being one of the most important life-sustaining elements on this planet, there is actually so much that is special about soil.
A quarter of all the life on Earth can be found beneath our feet. A square metre of soil can contain more than 10 000 different species, from microorganisms that cannot be seen by human eye, to megafauna such as moles.
These lifeforms are essential for enabling and regulating critical ecosystem processes such as carbon sequestration, greenhouse gas emissions, water storage and the uptake of nutrients by plants.
So soil really is the silent engine that keeps the planet alive."
Q: In your chapter, you discuss threats to soil biodiversity. Could you summarise what those threats are?
Alberto: "There are several threats to soil biodiversity. These include inappropriate land management practices, intensive agriculture, over-grazing, soil erosion, forest fires and poor water management - both irrigation and drainage.
Other practices – such as urbanisation and the conversion of grasslands or forest to cropped land – result in a rapid release of soil carbon to the atmosphere, which exacerbates global warming.
The Global Soil Biodiversity Atlas published by the JRC shows that mismanaging soils could worsen the effects of climate change, jeopardise agricultural production, compromise the quality of groundwater and worsen pollution.
Through the Atlas, we want to raise awareness of the importance of soil-dwelling organisms and propose solutions to protect soil biodiversity through the development of policies that directly or indirectly target soil health."
Q: You have created a map that shows the distribution of potential threats to soil biodiversity. There seems to be a clear division between the North and the South. Why is that?
Alberto: "The map represents a first, preliminary attempt to map threats to soil organisms at the global scale by taking into account eight potential threats.
The areas with the lowest level of risk to soil biodiversity are mainly concentrated in the northern part of the northern hemisphere.
We are talking about countries like Finland, Sweden, Canada and the northern parts of Russia which are scarcely populated.
These regions are less subjected to the direct effects of human activities, such as agriculture, although indirect effects – such as those caused by climate change – may become more significant in the future.
The areas at highest risk are those that are most exposed to human activities, for instance intensive agriculture, increased urbanisation and pollution.
Central and southern parts of Europe are included in the countries that potentially pose high risk threats to soil biodiversity.
Hopefully, in the future we will be able to further refine the map by including other pressures."
Q: Now let's look at the chapter on surface water. Alan, people are often interested in what lies beneath the surface, but your chapter is about what lies on the surface. Is this a deliberate play on words?
Alan: "It is indeed. We wanted to draw attention to the fact that people – especially in developed countries – often take water for granted, when really there is nothing about it that should be taken for granted.
Most of the water that life on Earth needs every day comes from surface water sources. Less than 0.01% of the total water on the planet is found in lakes and rivers, yet this water is the most accessible to us. It directly influences the distribution of plants and animals (and even toxins and disease), because it sits on the surface (and is in direct contact with the atmosphere).
It also affects climate, and we use it for transport and agriculture. Without surface water, hydroelectricity and thermoelectricity generation would not be possible.
This is why surface water is so important, and we need to protect it. We also need to know where it is, which is something that we have been working on recently at the JRC. Because believe it or not, people think that we have a good knowledge about the positions of our lakes and rivers, but we don't.
That's why, together with Google Earth Engine, we created the Global Surface Water Explorer. "
Q: You mention the Global Surface Water Explorer in your chapter of the Living Planet Report. Can you explain what it is exactly?
Alan: "The Global Surface Water Explorer was a massive project. We wanted to understand where the planet's surface water is located today, and we also wanted to see what had happened to the Earth's water bodies over time.
So together with a team from Google Earth Engine, we embarked on this project to analyse about 3 million satellite images collected by the NASA / United States Geological Survey Landsat programme since the 1980s.
These helped us to build up a picture of the changes in the occurrence of water on the Earth’s surface over the past three decades."
Q: The Global Surface Water Explorer captures the changes to surface water bodies from 1984 to 2015. What are the most important changes you detected during that period?
Alan: "We saw a lot of changes. We saw entire lakes disappear, rivers move and migrate, and entirely new lakes being formed. Sometimes these changes happened as the result of melting snow and ice, but often they were caused by dam construction – which of course changes biodiversity above and below the dam.
One of the examples is the Rio Grande/Rio Bravo basin, which stretches over 870 000 square kilometres of the south-western United States and northern Mexico. The river forms a natural boundary between the two countries and creates a thin line of life for millions of people and an incredible range of flora and fauna.
Over the last half-century, the condition of the river itself has changed significantly. Climate change, dams, water diversion, contamination and invasive species are changing this once vibrant, productive river. The Global Surface Water Explorer tracks the river’s comings and goings.
In parts of the river, the flow has diminished to a trickle, and sediment has buried prime aquatic and riparian habitat. As a result, populations of many native and endemic species have become locally extinct and the livelihoods of many riverside communities and citizens are compromised."
The Global Surface Water Explorer provides a new perspective on areas like this where the loss of freshwater is an ongoing crisis and where permanent loss could possibly be averted."
The report also contains a dedicated section on the recently published IPBES Land Degradation and Restoration Assessment, which was co-chaired by JRC scientist Luca Montanarella in his capacity as the Chair of the Intergovernmental Technical Panel on Soils (ITPS).
- Date de publication
- 30 octobre 2018