Tag Archives: 4 degrees

World Bank Wants off the Highway to Hell: Part Two

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‘Given that it remains uncertain whether adaptation and further progress toward development goals will be possible at this level of climate change, the projected 4°C warming simply must not be allowed to occur’ World Bank report

WHO: The Potsdam Institute for Climate Impact Research and Climate Analytics, commissioned by the World Bank

WHAT: A report looking at the impacts of 4oC of global warming and the risk to human systems

WHEN: November 2012

WHERE: The World Bank’s website

TITLE: Turn down the heat: Why a 4oC warmer world must be avoided

This is part two; part one is here.

What does a 4oC world look like?

It looks like a place where climate change has undermined economic growth through natural disaster after natural disaster which eventually overwhelms emergency response capabilities.

It looks like a world where all of the gains towards to the Millennium Development Goals of eradicating poverty and hunger have been wiped out by the negative impacts of climate change, and extreme heat stress has caused a 60% or more reduction in crop yield.

It looks like a world where even wealthy industrialised countries are no longer able to adapt to or meet development goals because of climate change and where entire coastal cities have been abandoned because the cost of fortifying them against rising sea levels was too great.

New York City in a 4oC world?
(Photo from New York Times Sunday Review Nov. 25th 2012 via ClimateProgress)

How could this happen? How could the change from 2oC to 4oC be the difference between continuing economic growth in a green economy and abandoned flooded cities?

Non-linear and cascading impacts.

Cast your minds back with me to high school math where you learned about exponential graphs. The ones that were y=x2 and you had to solve for x in your exams and it hurt your brain? This is non-linear and what is likely to happen with the planet. Take the oceans for example. While we still have sea ice in the Arctic, the warming from the oceans sucking up almost half of our carbon emissions every year is still relatively slow. However, once the ice melts and it’s all open water for the first time, that’s when warming gets going and it will likely ramp up like an exponential graph.

In fact, if you really feel like nerding it up, you can simulate sea ice at home and watch the tipping point happen. Put ice and water into a pot and once it’s cold (1-2oC) turn the heat on high and take the temperature every 30 seconds until the ice is all gone and the water is getting hotter (15-20oC or longer if you want). Graph the results and find your tipping point. Science!

Simulating Arctic ice melt: science! (photo: ©Adam Hart-Davis)

The final chapter in the World Bank report looks at the potential implications for a 4oC world in terms of risk management. If it’s going to cost a certain number of trillion dollars to prepare for 2oC, should we just double the amount and prepare for 4oC? They think that may not be enough since ‘lurking in the tails of the probability distributions are likely to be many unpleasant surprises’.

The report points out that since cascading effects are very difficult to predict, that most of the predictions I covered in part one are based on linear models and likely to be conservative estimates of what will happen with 4oC warming. They are also sector based and don’t take into account what happens when impacts team up and work together.

Going back to the oceans again, what will the cumulative impacts be of all the effects that have been studied separately? What happens when coral reefs collapse, marine production reduces from rising temperatures and acidification, low-lying coastal areas are inundated from sea level rise, and human economic and social impacts are all lumped together at the same time?

The report states that there is a high level of concern that all of those effects all happening together at once hasn’t really been studied or quantified beyond ‘horrifying’.

From what we know now from all of the leading research, this is a list of potential tipping points from the report:

1.5oC
This may be the coral reef tipping point which will create larger storm surges for coastal areas that were previously protected. It also means an economically significant loss of tourism dollars for places like the Great Barrier Reef.
This could also be the tipping point for the Greenland Ice Sheet which has been melting faster than expected (was previously predicted for 4.6oC). There is approximately 6-7m of sea level rise in this ice sheet, so New York City may need to move inland.

3oC
This could be the tipping point for the Amazon Rainforest, where large parts of the rainforest die off from lack of water and release more carbon into the atmosphere, further fuelling climate change in a positive feedback loop that it will be almost impossible to recover from.
This could also be the point for the West Antarctic Ice Sheet which has 3m of additional sea level rise stored in it. New York City will need to keep moving.

4oC
This is the probable tipping point for world agriculture as crops start dying from heat stress. The IPCC assessment predicts that crop yields will decrease between 63-82%. Keep in mind that this goes hand in hand with a population increase to 9 billion people.
This is also the point at which the accumulated stresses from 2oC and 3oC overwhelms emergency and health services and all of the gains made to alleviate poverty are also overwhelmed by the negative consequences from climate change.

Once the World Bank has laid out for us exactly how horrible it could possibly get in a way we can’t easily predict, plan for, adapt to safely or afford, this is the very simple conclusion they have that we should all be able to agree with:

‘Given that it remains uncertain whether adaptation and further progress toward development goals will be possible at this level of climate change, the projected 4°C warming simply must not be allowed to occur—the heat must be turned down. Only early, cooperative, international actions can make that happen.’

World Bank Wants off the Highway to Hell

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“It is my hope that this report shocks us into action… This report spells out what the world would be like if it warmed by 4 degrees Celsius… The 4oC scenarios are devastating.” Dr. Jim Yong Kim President, World Bank

WHO: The Potsdam Institute for Climate Impact Research and Climate Analytics, commissioned by the World Bank

WHAT: A report looking at the impacts of 4oC of global warming and the risk to human systems

WHEN: November 2012

WHERE: The World Bank’s website

TITLE: Turn down the heat: Why a 4oC warmer world must be avoided

Following on from last week’s Highway to Hell post, the World Bank released a report looking at the human system implications for climate change because things that disturb the current systems of running the world tend to be expensive for organisations like the World Bank.

The report looks at climate change projections for a 4oC world, most of which I’ve already covered on this blog like; ocean acidification, droughts, tropical cyclones, sea level rise and extreme temperatures. So I’m going to skip ahead to the chapters on impacts in different sectors and then my personal favourite, non-linear impacts. This week will be sector impacts.

It’s refreshing to see an organisation that is normally known for its staid and stuffy conservatism talking about climate change reality. The foreword by the World Bank’s President says no less than that the science is unequivocal, that warming of 4oC threatens our ability to adapt and that meeting the currently agreed upon UNFCCC targets (which we’re not meeting) will lead to 3.5-4oC warming which must be avoided through greater and more urgent action now.

Let’s look at what this bastion of the three piece suit with not a dreadlock in sight says about the impacts that could be felt in a 4oC world.

Agriculture
Generally the impacts for agriculture will be regionally specific, as will the impacts for climate change. Some regions will get more rain, some less rain, and the timing of the seasons will change.

The favourite argument of luke-warmists is that increased CO2 in the atmosphere is excellent because it will benefit agricultural growth and we’ll be able to grow lettuce in Siberia. Well, yes and no – it’s more complex than that. Between 1-3oC of warming it’s likely we’ll see increased yields in certain regions from CO2 fertilization. Beyond 3oC productivity will decrease as the stresses of other climate change impacts outweigh any benefit from extra CO2.

And even then, demand from a world population growing to a projected 9 billion by 2050 is going to increase demand by 70-100% for agricultural food products, so even without the costs of climate change reducing the productivity of crops, it’s going to be difficult to feed the world with that many people.

Another vulnerability for agriculture is sea level rise and salination of some of the world’s most productive agricultural land. Having to move your farm from a nutrient rich delta to less productive soil further inland will detrimentally affect crop yields.

Finally, the benefits of CO2 fertilisation will be limited by the availability of other nutrients. You can give a plant all the CO2 it wants, but if you don’t also give it nitrogen, phosphorus and water, it’s not going to grow any faster. It’s currently looking like there’s going to be a world shortage of phosphorus based fertilizer, which will have a very detrimental affect on world crops that need to be becoming more productive to feed a growing population, not less.

Water Resources
This section starts with a very obvious statement that is useful to point out: ‘The associated changes in the terrestrial water cycle are likely to affect the nature and availability of natural water resources and, consequently, human societies that rely on them.’

We rely on the services that the environment provides for us and the second most important one of these is water (the first one is air).

As well as the expected (and already occurring) more severe droughts, river runoff is expected to decrease significantly in areas where the water is used for both agriculture and transport like the Danube, the Mississippi, the Amazon and the Murray-Darling Basin in Australia.

In a 2oC warming world, most of the water stresses can be expected to be from population increase. By the time we get to a 4oC world, the stress of climate change will outstrip that of population increase. Even in the areas where there will be increased rainfall, it’s not likely to come at the right time of the year, or it could come all at once causing flooding.

There’s a lot of uncertainty in many models of drought prediction and rainfall prediction as well as the possible effects for specific regional areas, but the conclusions that are coming from all of the studies identified in this report range from bad to very bad, and in a 4oC world almost half of the world’s population could be water stressed by 2080.

Ecosystems and Biodiversity
This is the fun section that starts using terms like ‘mass extinction’ and gets everyone Googling things like the Eocene.

Biodiversity is, in my opinion going to be the ‘sleeper issue’ of climate change, because it happens over longer periods of time and is easy to ignore as out of sight out of mind for us urbanites until it’s too late. As the report quotes; ‘It is well established that loss or degradation of ecosystem services occurs as a consequence of species extinctions’.

There’s also the issue of thresholds. Where an animal or plant or ecosystem can absorb a certain amount of degradation, until you reach the tipping point and it can no longer take it. Some areas will be able to absorb more warming (Canada, Northern Europe) while others may reach biodiversity and ecosystem tipping points earlier (Pacific Islands, Bangladesh).

In a 4oC world, it’s possible that habitats could shift by up to 400km towards the poles, which is fine if you’re a mosquito moving north from Mexico, but not so good if you’re a mountain rabbit and you run out of mountain.

And here’s some food for thought: the report states that if the planet lost all of the species that are currently listed as ‘critically endangered’ we would officially be living through a mass extinction, and if we lost the species that are also ‘endangered’ or ‘vulnerable’ we would be confirmed as the sixth mass extinction in geological history. Which means history would list the dinosaurs and then the humans in the fossil record of mass extinctions.

As the report says: ‘loss of biodiversity will challenge those reliant on ecosystem services’. This means all of us.

Human Health
Like smoking, climate change is bad for your health. The above mentioned agricultural and water issues with a 4oC warmer world will lead to famine and malnutrition on a large scale. The extreme weather events from a planet on climate steroids will kill people in heat waves, increase respiratory diseases and allergies from the extra dust in the droughts, weaken existing health services through damage to hospitals in extreme storms, flooding and so on.

Living with constant extreme weather is bad for your mental health, whether it’s the slow and painful crush of watching drought destroy your farmland or the fast emergency of cyclones, hurricanes and floods.

And remember the mosquitoes moving north? They’ll bring new tropical diseases with them that will infect many new people who have never developed any immunity to them.

Given all of the above, it’s pretty clear why the World Bank wants off the highway to hell. Because they’re concerned about both loaning money to countries that are dealing with these catastrophes, and living through these impacts. Because, as all of my fellow Gen Ys already know, living these impacts by 2050 is not some vague and distant future. It’s before we all retire.

 

Next week: non-linear impacts, which are scarier than they sound.