Published: 23 December 2013

Still time to change Earth’s long-term forecast

Jørgen Randers

After a lifetime promoting sustainability – sadly, with limited success – last year I sat down to consider what will happen to my beloved world over the next 40 years. The main question I asked myself was whether I should continue worrying about the future during my final 20 to 25 years here on Earth.

Young Australians take a stand against climate change inaction at the 2009 Power Shift event – the first of six – coordinated by the Australian Youth Climate Coalition. Professor Randers says ‘young people can see from past experience that there will be insufficient investment in solutions [to climate change mitigation and adaptation]’.

Credit: Daryl Orillaza for AYCC

My answer is in 2052 – A Global Forecast for the Next Forty Years. The main message is simple: I predict that the world average temperature will surpass 2 degrees Celsius above preindustrial times – the internationally agreed danger threshold – in 2052. And the temperature will continue rising, condemning our grandchildren to the likelihood of climate disaster in the second half of the 21^st century.

This means that the global future will resemble one of the 12 scenarios from The Limits to Growth, which I co-authored in 1972. The world will resemble the ‘persistent pollution scenario’, with carbon dioxide as the ‘persistent’ pollutant which, once emitted, resides in the atmosphere with a half-life of 100 years. (For more on the original Limits to Growth forecasts and how they fared compared to reality, you can read this CSIRO discussion paper or this article in The Conversation.)

I do not forecast an energy crisis, a resource crisis, a food crisis, a water crisis – but neither do I expect to see one of the more optimistic ‘sustainability’ scenarios from Limits to Growth. I believe that man-made greenhouse gas emissions will prove to be the real problem.

This is because the human footprint will be smaller than most people expect. The future world population and gross domestic product (GDP) will be much lower than commonly forecast: the global population will peak at 8 billion around 2040, and the world GDP will only grow at 2 per cent per year to 2052 – half historical rates.

There are two major reasons: women will choose to have fewer children and economies will find it more difficult to grow as they mature. As a consequence, humans will use fewer resources and rising greenhouse gas emissions will be the critical factor shaping our life on Earth.

Climate change will trump resource scarcity. One consequence will be a smaller world economy in 2052. Another will be more poverty than commonly forecast.

Climate emissions could easily have been reduced if humanity decided to take action, but humanity won’t because of myopia: simply look at the tepid goals and strategies adopted by the Rio+20 summit last year and the negative reaction from the younger generation of climate activists, who ripped up the negotiating text in protest.

Young people can see from past experience that there will be insufficient investment in solutions. A good life for our grandchildren is being sacrificed for short-term gain for ourselves. In modern democratic market economies, investments mainly flow to what is profitable, not what is needed.

The short-term nature of markets could be modified by legislation – with, for example, a tax on carbon. My point is that this is unlikely to happen in democratic society, because the voter is focused on short-term income growth. Most voters won’t support higher prices for gasoline and electricity.

Another solution could be new multi-national institutions (like the European Union or World Trade Organization) that impose a common long-term perspective on nation states. But a full 20 years of talking after Rio 1992 has produced little progress.

Luckily my forecast is a cliff hanger.

A small change in the human response would suffice to create much better life for our grandchildren. For example, shifting 1 to 2 per cent of the global workforce and global capital into climate-friendly sectors would do the trick.

Workers could make electric cars rather than fossil-fuelled ones, build solar plants rather than coal-fired plants, and construct smaller well-insulated homes rather than big un-insulated ones. The income loss would be small, but the effect on distribution – the split between now and the future – would be big and desirable.

We also need to introduce systems of governance that place more emphasis on long-term effects. Global society needs structural long-termism to counter current short-termism: for example, a world climate bank for greenhouse gas emissions rights.

Concretely, in order to create a better world for our grandchildren, we should:

have fewer children, especially in the rich world
reduce the ecological footprint, first by slowing the use of coal, oil and gas in the rich world
construct a low-carbon energy system in the poor world, paid for by the rich
create institutions that counter national short-termism.

But, most importantly, the coming crisis should be used to develop new goals for modern society – to remind us all that the purpose of society is to increase a total life satisfaction, not only to have each person contribute to the gross domestic product.

Jørgen Randers is Professor of Climate Strategy at BI Norwegian Business School where he works on climate and energy issues, scenario analysis and system dynamics. He is a non-executive member of several corporate boards in Norway, and also sits on the sustainability council of The Dow Chemical Company in the US and (until recently) of British Telecom in the UK. Professor Randers co-authored The Limits to Growth (1972) and its sequels in 1992 and 2004. This article was originally published in The Conversation.

Published: 19 January 2015

Mapping East Asia’s disappearing tidal flats

Nick Murray

Who speaks for the tidal flat? There are many voices for the mangrove forest, the coral reef and the seagrass meadow, but the chorus for the mud, sand and silt flats that sit hidden under shallow water for most of the tidal cycle is often silent.

In China alone more than 1.2 million hectares of wetland reclamation has taken place in the last 50 years, perhaps accounting for more than 5 per cent of the worlds’ tidal wetlands.

Credit: Nick Murray

Not only do hundreds of species of migratory bird depend on them for their existence, this coastal ecosystem also protects large chunks of humanity and provides ecosystem services to hundreds of millions of people around the world.

A zone under pressure

The problem for all coastal ecosystems is the shifting character of the coastal zone. The last 50 years has seen the global human population migrating rapidly to coastal regions. As a result, coastlines around the world have become a focus of expansion of urban, agricultural and industrial areas.

This development is having a major impact on coastal ecosystems, which has resulted in the widespread loss and degradation of ecosystems such as mangroves, seagrasses, coral reefs and tidal flats. And that has major consequences for humans and nature.

In terms of the human cost, coastal ecosystems are a frontline defence that protects billions of dollars of infrastructure from storms and sea level rise, and maintaining their integrity is among the most cost-effective options for coastal protection.

Tidal flats are a widespread coastal ecosystem that is frequently overlooked in the planning and management of coastal resources. They are among the most widespread of any coastal ecosystem and, as well as providing ecosystem services to hundreds of millions of people worldwide, they sustain a suite of threatened and declining species.

For instance, tidal flats support the majority of the world’s migratory shorebird species, enabling their yearly migration from the arctic to areas as far south as Patagonia. Unfortunately, their proximity to centres of human population have also made these areas targets for cheap and rapid coastal development.

Drawing a mud map

So, what’s the magnitude of the problem?

Until now we have had no way of knowing just how much of this declining coastal ecosystem has been destroyed, or how much and where it remains. The principal reason for the lack of accurate maps of this ecosystem is due to the rapidly changing conditions they encounter: changing tides either expose or cover them, severely limiting the application of classical remote sensing methods.

To solve this problem, our small team of remote sensors and spatial ecologists have been developing methods to map tidal flats over very large areas.

Using the heavily developed tidal flats of mainland East Asia as a case study, we have developed a rapid mapping approach for identifying the distribution of tidal flats while assessing their changing status at continental scales.

The tidal flats in this region – which fringe the countries of North Korea, South Korea and China – are among the largest in the world, measuring up to 20 kilometres wide in some places. Our methods – utilising free data from the US Geological Survey’s Landsat archives and freely available regional tide models – allow fast implementation across thousands of kilometres.

Indeed, with more than 28,000 images to choose from, we determined the changing status of tidal flats across more than 14,000 kilometres of coastline.

Easily overlooked, and invisible for much of the tide cycle, mud flats are disappearing right before our very eyes. And their loss comes with an enormous cost.

Credit: Nick Murray

Impacts of reclamation

Our results demonstrate that tidal flats in East Asia are being destroyed at rates similar to other major at-risk ecosystems, such as tropical forests and mangroves. The principal cause of these losses related to coastal development. Changes to sedimentation regimes due to the damming of major rivers is also an issue as this results in offshore losses of tidal flats.

In East Asia, land scarcity is a severe issue and often the cheapest method of acquiring land for large coastal developments is through land creation, often termed reclamation. Tidal flats, which are generally characterised by low-sloping flats in areas protected from severe weather, have proven an ideal environment for cheap and rapid coastal development.

This radical transformation involves the construction of seawalls, infilling and finishing for land use. These areas are then developed into new parcels of land for aquaculture, agriculture, suburbs and industry.

Loss of coastal wetlands to land reclamation is a global problem that is severely affecting the world’s coastlines. In China alone more than 1.2 million hectares of wetland reclamation took place in the last 50 years, perhaps accounting for more than 5 per cent of the world’s tidal wetlands according to some estimates.

This is clearly a symptom of China’s rapid coastal urbanisation. This arc of growth will form one of the world’s largest urban areas by 2030 – a continuous coastal urban corridor over 1800 kilometres long.

The rapid pace of coastal population growth and sea-level rise – as well as increasing demand for aquaculture, coastal wind farms, and tide energy – will certainly apply further pressure to the world’s tidal flats in the future.

The loss of tidal flats along migratory pathways, especially staging sites (where birds must replenish their energy stores during migration for long, energetically expensive flights) can have extreme consequences for shorebird populations. For the millions of shorebirds that migrate through the East Asian-Australasian Flyway, the intertidal areas of Asia are a crucial migratory bottleneck.

Credit: Nick Murray

Uncertain future

An effective conservation strategy must manage the complex economic and social trade-offs that drive coastal development.

Decision-making that simultaneously plans for coastal development and coastal conservation along the world’s most rapidly developing shores is clearly needed.

For example, places where natural values have effectively been lost due to sediment depletion and coastal subsidence could be prioritised for development. As part of a carefully integrated plan, this could ease pressure on a functioning network of coastal protected areas and ensure continued delivery of ecosystem services.

Not only might this avert catastrophic extinctions of coastal biodiversity, it will also help us ensure we have a coastline capable of adapting to an increasingly uncertain future.

Dr Nick Murray is a Research Associate at the Centre for Ecosystem Science, University of New South Wales. He carried out this research in association with the Environmental Decisions Group (EDG), while completing his PhD at the University of Queensland. The EDG is a network of conservation researchers developing the science of effective decision making to better conserve biodiversity, and includes a number of Australian and International research centres, including CSIRO. This article first appeared in Decision Point – a free monthly online publication from the EDG.

More information

‘Tracking the rapid loss of tidal wetlands in the Yellow Sea’, published in Frontiers in Ecology and the Environment

‘Continental scale mapping of tidal flats across East Asia using the Landsat archive’, published in Remote Sensing

‘IUCN situation analysis on East and Southeast Asian intertidal habitats, with particular reference to the Yellow Sea (including the Bohai Sea)’, IUCN occasional paper

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