Professor Robert Watson, Chief Scientific Advisor to DEFRA, speaks about food security, climate change and our natural environment

March 19th, 2011 by Professor Robert Watson

Professor Robert Watson, Chief Scientific Advisor to DEFRA, speaks to the SDUK Conference about food security, climate change and our natural environment (click image to expand - ©RLLord)

This is an edited transcript of the presentation by Professor Robert Watson, Chief Scientific Advisor to the UK Department for Environment, Food and Rural Affairs (DEFRA), to the SDUK Conference on 17 March 2011 at the QE II Conference Centre in Westminster, London


“We already know enough to act much better than we are now.  We are not knowledge short.  We lack political will.

Fundamentally, and I am going to give a slightly UK DEFRA perspective.  There are three major issues: climate change, food security, and looking after the natural environment all the way from air quality to our natural ecosystems – all of it within the concept of a green economy.

The key issue is that all of these issues are interchanged and inter-coupled.  You can’t look at food security without climate change or looking at our natural ecosystems.  You can’t look at natural ecosystems without looking at food security or looking at climate change.  We need an inter-multidisciplinary way.

Social research is sadly lacking and absolutely critical to understand.  It’s not just getting policies right.  It is not just getting technologies right.  It is understanding behaviour all the way from the individual to communities, all the way up of course to the private sector and the public.

There is absolutely no question that the climate is changing. We’re changing atmospheric composition.  We’re seeing warmer temperatures.  We’re seeing changes in precipitation patterns.  Mountain glaciers are retreating.  The Greenland ice sheet is retreating.  And we are seeing more severe weather events from major droughts and floods.

We have tried to do a probabilistic scenario of what should happen in the UK.  We have run the model 400 times for a low, medium and high emissions scenario.

For the medium scenario for the decade of the 2080s, the central estimate is that the UK would warm by 4 or 5 degrees Celsius but it is a probabilistic scenario.

If we were lucky it might only warm by 1 or 2 degrees Celsius, may be 3 degrees Celsius.  If we are unlucky, there’s a ten percent probability we’re going to see the UK warm by 7, 8, 9, 10 degrees Celsius.  That’s only the medium emissions scenario.

If we go to the high emissions scenario there’s a ten percent chance we are going to see increases in temperature in the UK especially in southern England greater than 10 degrees Celsius, possibly up to as much as 12, 14, 15.

What about precipitation?  Overall not much change in annual precipitation – plus or minus ten percent.  That’s the very top set of figures.  But major changes we would project in the distribution of precipitation over the year.  Effectively, in the winter it would be much wetter, potentially getting up to 20, 30, 40 percent wetter in winter (a ten percent chance).  But what would happen in the summer – much dryer.  Typically 30 to 40 percent dryer but there’s potentially a chance of 70 or 80 percent dryer in the south-west of England, so potentially significant changes in both temperature and precipitation, and you cannot rule out these ten percent chances.  So the question is from a precautionary standpoint to what degree do we try and adapt to the central estimate. We can be optimistic on the low end or do we try and adapt to the high end?

And we also have to remember there is ocean acidification as we put more carbon dioxide into the atmosphere more of it gets converted into carbonate ions into the ocean and we get a change in ocean acidification with potential adverse effects on fishing and on coral reef systems.

So what are the risks?

Both nationally and globally are risks of food security, water quantity and quality, increased risks of floods and droughts in the same geographic area in the same year, significant changes of biodiversity in the ecosystems that we rely on, impacts on human health and impacts on infrastructure, flooding, coastal erosion, sea level rise.  These are major threats.

We have also got to realise that it is also a potential threat of conflict.  If we think of sub-Saharan Africa where we have already got poor governance, poor people – and also in small island states, and also in low-lying deltaic areas such as Bangladesh, tens of millions of people could potentially be displaced due to sea level rise.

Food shortages – in the areas we have food shortages – sub-Saharan Africa.

Water shortages in the arid and semi-arid areas throughout much of the developing world.

Natural resources being depleted because of climate change and other stresses.   All of these add-up to effectively a potential for conflict, which will depend very much on the socio-economic political situation in those countries.  So we have major threats to various sectors.  We have major threats to the potential, and I do stress ‘potential’, spread of conflict.

What’s the goal?  Well, we want to try and limit (to an average temperature rise) of about two degree Celsius.  Everyone says they want to do it but I have to be quite honest, the rhetoric far exceeds action.

We need to try and limit two degrees because if we go much higher we will see significant adverse effects as I have already said on ecosystems, water, food and security.

So what is the challenge?

Well, if you want a 50:50 shot of stabilising at two degrees Celsius we have to stabilise around 400 parts per million c02 equivalent – that’s carbon dioxide plus all the other greenhouse gases, partially offset by the fact that we have also polluted our atmosphere with sulphate aerosols that luckily for us – one good feature is that it partially offsets the projected global warming.

Well, we are already at 385 parts per million of c02 equivalent today and given that much of the world wants to reduce their sulphur emissions in China and India then this offsetting affect will disappear.

I think we have almost zero chance of stabilising at 400 parts per million, and I also think we have almost zero chance of stabilising at two degrees Celsius unless we are incredibly lucky.  I think we are on the way to a world of three or four degrees Celsius (increase in average global temperatures), not two degrees Celsius.

Professor Robert Watson, Chief Scientific Advisor to DEFRA, gives a sobering talk on society's efforts to curb climate change to the SDUK Conference (click image to expand - ©RLLord)

The United States is not moving and with the recent change in the House as well as a significant shift in power in the Senate they’re not likely to do very much.  If the USA doesn’t do very much will China?

China is doing a lot more than most other countries in the world but has also got major economic growth so even though they’re probably doing better than almost any other country in energy efficiency, thinking of renewable energies, there overall economic growth of eight to ten percent per year is still driving up carbon dioxide emissions.

The first speaker said we’re doing really well in England.  We’re on target for a 35% reduction in greenhouse gas emissions by 2015 – 2020 and indeed at the moment we’re somewhere like 20 t0 22 percent below greenhouse gas emissions today.

What a success!  No!  If you count embedded carbon we’re actually plus 12 percent above our 1990 measure. So all we’re doing is off-shoring our carbon footprint to other countries in the world.  So at first sight it looks like we’re doing really well. We’re not!  We’ve not significantly changed our habits in the last number of years and some of the reasons we’re using less transportation is the economic cost of fuel.  It is not simply that we’re trying to change our driving habits very significantly so we’re got to be very careful what we do with numbers.  It is an inconvenient truth but it’s a truth we all need to know about.

What are some of the challenges?

We need even better probabilistic projections of climate change especially focusing on extreme weather events – potentially non-linear effects, which could occur in the system.  And from a DEFRA point-of-view we need to understand greenhouse gas emissions.

Professor David MacKay did an excellent job of showing all the different sectors we need to look at and it’s not just the energy sector that is in David’s model.  We have to look at agriculture sector as well.

We need to understand the impact on all sectors and ecological systems including the non-linear responses – the surprises that might be in the system.

We have to look at opportunities, barriers, economic costs, and social implications of both how you transition to a low carbon economy, and how we adapt to climate change.

There are thoughts of doing geo-engineering in the world.  I am cautious about that, very cautious.  If indeed we should examine it, and we should at least look at the research for climatic and other environmental implications.

If we look at the UK National Ecosystem Assessment that Steve Albon and I co-chair with 500 experts in the UK – we looked at the drivers for change, how it would effect ecosystems, how it effects ecosystem services, the goods that we (society) use, and implications for human well-being.

We have looked at the provisioning services – the provisioning of food, timber, pure water; the regulating services – climate change, air quality, pollination services; the cultural services – aesthetics, spiritual, recreational; and the underlying supporting services – soil formation etc.

The reason we are losing biodiversity and degrading our ecosystem services. We have largely focused on increasing the provisioning services – the food we eat, the timber we use.  Those things add market value.  They have come at a major expense of regulating cultural services because they have to date had limited if any market value.  We looked at the eight broad habitats in the UK and how they effectively all impact on the provisioning cultural services.

Preliminary analysis of relative importance (coloured cells) of different habitats and change over last 20 years with them (arrows) in delivering ecosystem services across the UK. It will differ at different national, regional and local scales (This representation subject to revision before the National Ecosystem Assessment is completed)

Dark green means it is a very important habitat for a particular service.  White means it is not important at all. Light green is somewhere in the middle.  And the direction of the arrow says are things getting better or worse in the UK.

Roughly 30 percent of the arrows are going down.  That is 30 percent of the services in the UK are still degrading in spite of all the regulations we have got in place on air quality, water quality. In spite of the fact that we have the agricultural environment schemes and the pillar too of the European Union.  About 20 percent are improving.  Things are a lot better than they used to be especially on water quality and air quality – at least the chemical part of water quality but not the biological part.  So clearly we are doing better than we were but we can do a lot better.

Drivers of biodiversity change for different biodiversity groups in the UK (source: National Ecosystem Assessment, October 2010)

This chart was looking at the basic drivers – there are five basic driver: agri-conversion of ecosystems, over-exploitation of ecosystems, pollution, climate change, and invasive species.

And as you can see ‘red’ means its bad, and therefore, typically the major drivers to date have been over-exploitation, conversion of ecosystems and pollution.  Climate change has not been a big driver to date either in the UK or internationally except for polar systems but it will become either the, or one of the major drivers in the next 50 years.

The key point is getting the economics right and what we have done in the National Ecosystem Assessment is to say we have lots of services but the only ones you actually have to value directly so you don’t double count are the final ecosystem services that give us the goods that we use.

Valuing ecosystem services published in the UK National Ecosystem Assessment (click image to expand)

And so we have a new approach of how to value it in economic terms, recognising their social value that can’t be put into an economic framework as well.  We are working through what is the value of these ecosystem services and it is considerable. Very, very considerable and therefore we have got the economic system completely screwed up that we don’t value these non-market values.  We see it as a ‘+’ on the right hand side. That says that there are other values that cannot be put into an economic framework – some things to do with mental well-being.  Green spaces are extremely important.

So what are some of the major conclusions?

Make sure we value all ecosystem services, not just those bought and sold in the market.  Make sure you don’t have perverse subsidies in agriculture, fisheries and energy.  Pay landowners not only for the food or the timber they grow but pay them for all the ecosystem services.  Make sure we have appropriate pricing policies for scarce resources such as water and make sure we have market mechanisms that work.

So what do we have to understand?

We do need a better understanding between biodiversity and services that ecosystems provide.  We do need a better understanding of the response of the habitat to both the direct and indirect drivers of change.  We do need a better understanding between the services and human well-being but a key part is getting the economics right so that when we value all of these services it will be taking place in both national decision making and local decision making.  So there’s a major research challenge that will require multidisciplinary research from the natural scientists, the economists, the social researchers, the technologists etc.  In essence we have to understand what is the true economic value of our services and how do we appropriate that value to the local landowner.

Professor Robert Wallace tells the SDUK Conference audience we need political will and we can do better (click image to expand - ©RLLord)

Food – a major challenge.  Overall a phenomenal success story.  Total food production in the world has gone up by almost a factor of three in the last 50 years.  Except for the small food price spikes we have seen in the last couple of years, food is an all time low in price but we still have one billion people going to bed hungry every night, and significant environmental degradation – either greenhouse gas emissions, loss of biodiversity, land and water degradation.

The challenge is to double food availability – not food production – within the next 50 years.

We waste 40% of all food produced in both developed and developing countries.  So one of the challenges is to reduce food waste.  But as we meet this demand for food there will be less labour, less water, less arable land, high energy prices, distorted trade policies, and environmental issues.

So the option for Action?

We have to embed economic, environmental and social sustainability into agricultural policies, practices, and technology.

We know enough today to feed the world. We are not limited by our knowledge of science and technology.  We can feed the world today.  The problem is rural infrastructure in developing countries is broken.  We need to empower women in developing countries.  We need micro-finance.  We need better roads. And advanced biotechnology may be needed for the challenges of the future such as climate change, new and emerging pests but we need to understand the risks and the benefits of all technologies, and we need to reform our international trade, and its mainly as I say, rural development.  A series of agricultural challenges – how do we improve the crops – drought resistant, temperature resistant, pest resistant, and salinity resistant?  How do we reduce the inputs of fossil fuel?  How do you reduce the greenhouse gas emissions?  And how do we reduce waste and at the same time improve food safety?

In conclusion, climate change is rapidly changing, biodiversity is being lost at an unprecedented rate.  We need to bring together economic, environmental and social aspects of both climate change and biodiversity.  They effect food, water, energy and human security.  We need a package of policies, practices, technologies and behaviour change.  We need to get the economics right.  We need to go beyond rhetoric and start to have action.  Thank you.”

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