Don’t go in the Water

Warming sea surface temperatures in low-salinity oceans like the Baltic Sea is increasing cases of Vibrio bacteria infections

WHO: Craig Baker-Austin, Nick G. H. Taylor, Rachel Hartnell, Centre for Environment Fisheries and Aquaculture Science, Weymouth, Dorset, UK,
Joaquin A. Trinanes, Laboratory of Systems, Technological Research Institute, Universidad de Santiago de Compostela, Spain, National Oceanic and Atmospheric Administration, National Environmental Satellite Data and Information Service, CoastWatch, Maryland, USA
Anja Siitonen, Bacteriology Unit, National Institute for Health and Welfare (THL), Helsinki, Finland
Jaime Martinez-Urtaza  Instituto de Acuicultura, Universidad de Santiago de Compostela, Spain

WHAT: Establishing patterns between Vibrio bacteria infection outbreaks and climate change in the Baltic Sea to be able to predict future outbreaks.

WHEN: January 2013

WHERE: Nature Climate Change, Vol 3, January 2013

TITLE: Emerging Vibrio risk at high latitudes in response to ocean warming (subs. req)

Imagine that it’s a hot summer’s day in Northern Europe. The heat wave has lasted for more than three weeks now and you’re just dying to get into the ocean for a swim to cool off, except that you can’t, because there’s been a bacteria outbreak in the water and going swimming will make you sick.

Looks great! Can’t swim. (photo: flickr)

Looks great! Can’t swim. (photo: flickr)

It doesn’t sound like fun does it? But it’s happening increasingly in the Baltic Sea, and it looks like climate change is providing the exact conditions these bacteria love.

Vibrio is a type of bacteria that grows really well in warm (>15oC) low-salinity (<25 parts per trillion salt) water. The most common type in estuaries and other shallow water is Vibrio vulnificus, which is related to the same bacteria that causes cholera (Vibrio cholerae). Not a nice family, really.

When you swim in water that has Vibrio bacteria, it immediately gets excited (yes, I’m aware that bacteria don’t have feelings) about any cuts or wounds you have and infects them giving you symptoms like vomiting, diarrhea, abdominal pains and blistering dermatitis. Well, that’s a way to really ruin your summer.

If you’re really unlucky or immuno-compromised, Vibrio will give you blistering skin lesions, septic shock (life threatening low blood pressure) and possibly kill you 25% of the time. It’s an efficient bacterium though, and will kill you in only 48hrs.

Vibrio vulnificus (Wikimedia commons)

Vibrio vulnificus (Wikimedia commons)

So why is Vibrio moving into the Baltic Sea more often? Climate change, combined with location.

The Baltic Sea is the largest low-salinity marine ecosystem on Earth, and is surrounded by highly populated countries, meaning there are 30million people living within 50km of the shores of the sea. The Baltic Sea is also warming rapidly.

The Baltic Sea (Google maps)

The Baltic Sea (Google maps)

The researchers found that the sea surface temperature has been warming in excess of 1oC per decade, which is seven times the global average rate of warming. The rate is also increasing. From 1850 to 2010, the rate of warming was .51oC per century. The warming between 1900 to 2010 was at a rate of .77oC per century, and more recently the warming from 1980-2010 has been at a pace of 5oC per century, which is scarily fast for planetary systems.

Their data shows that for every 1oC increase in the summer maximum sea surface temperature, the rate of observed Vibrio infections increased by almost 2 times. This of course, gets compounded with the fact that increased summer maximum sea surface temperatures mean the air temperature is also hotter, and a hotter summer means more people head to the beach and get infected.

Even worse, recent research shows that some Vibrio bacteria’s ‘pathogenic competence’ (which is scientist for how good it is at infecting you) could be improved by increased temperatures.

Which all adds up to a nasty sequence of events where many more people than usual get nasty skin lesions. So what should we do about it? The researchers suggest monitoring conditions and sending out health advisories for when the sea surface temperatures are >19oC for three weeks or more as well as using predictive models to try and work out where/when the worst outbreaks might occur.

I don’t know about you, but nasty bacterial infections from a warmer ocean on a slowly cooking planet doesn’t sound like a good idea to me. So I’d also like to suggest we stop burning carbon so I and the people of Northern Europe can continue to swim in the summer.

IPCC vs Reality: Who Got it Right?

How did the projections from the IPCC 3rd and 4th reports match up against recorded temps for the last decade?

WHO: Stefan Rahmstorf, Potsdam Institute for Climate Impact Research, Germany
Grant Foster, Tempo Analytics, Garland, Maine, USA
Anny Cazenave, Laboratoire d’Etudes en Géophysique et Océanographie Spatiales, Toulouse, France

WHAT: Comparing the projections from the IPCC 3rd report in 2001 and the IPCC 4th report in 2007 to the observed climate data to 2011

WHEN: November 2012

WHERE: Environmental Research Letters Vol 7, No. 4 (2012)

TITLE: Comparing climate projections to observations up to 2011

The IPCC. It is the favourite punching bag of climate deniers and conspiracy theorists alike, who all like to claim that the reports are faulty or flawed or incorrect. So these researchers decided with the 5th Assessment Report due soon to go back to the 3rd and 4th reports, check what was in the projections and see how accurate they were on temperature rise and sea level rise. Kind of like a mid-term report card!

Five years ago, the CO2 concentration and global temperatures were closely following the projections of the IPCC 3rd report, and sea level rise was tracking along the upper limit of the uncertainty range. So where the sea level rise projections were plus or minus several millimetres a decade, the observed data was only on the plus side. How did the projections look with an extra five years of data?

The IPCC projections didn’t attempt to include the effect of solar variability, volcanic eruptions or El Niño in their temperature models because those things are random and therefore pretty impossible to predict in the future. The observed data was adjusted to remove the random variability from solar, volcanic and El Niño effects so that the researchers were comparing apples to apples when trying to assess the accuracy of the IPCC projections. For those playing at home, they used a multivariate correlation analysis (yeah, I love those too!).

The data adjustment removed the cold anomaly from the 1992/3 Mt Pinatubo eruption, and the ‘exceptionally high’ 1998 temperature maximum from the extreme El Niño event.  The observed data showed warming of 0.3oC from 1990 to 2011. The IPCC 3rd report projected 0.2-0.4oC warming to 2011 and the 4th report projected 0.3-0.5oC warming. So for temperature increases, the IPCC was pretty much spot on.

3rd report projections in blue, 4th report projections in green, observed data in red, shaded areas are the uncertainty range. (from paper)

3rd report projections in blue, 4th report projections in green, observed data in red, shaded areas are the uncertainty range. (from paper)

So what about sea level rise? The IPCC got that one wrong, but not in a way that climate deniers can celebrate – they underestimated it by 60%.

Sea level rise: measured data in red, third assessment in blue, fourth assessment in green (from paper)

Sea level rise: measured data in red, third assessment in blue, fourth assessment in green (from paper)

The IPCC best assessment was 2.0mm per year of sea level rise, and the satellite based recorded data is actually 3.2mm per year (±0.5mm error range). The researchers tried to work out if the huge difference between the projection and the recorded data was because of variability over recent decades, and decided it was unlikely because the IPCC similarly underestimated the sea level rise from 1961-2003. It was even more unlikely because the rate of sea level rise over the past 130 years has a ‘highly significant correlation with global temperature’.

This is scientist for almost identical, because those of you that read the IPCC 3rd report will remember that when the IPCC says ‘very likely’ they mean there’s a 90-99% chance it will happen. Talk about understatement.

What did the IPCC miss for sea level rise? Well firstly, it’s worth mentioning that most of the world’s scientific community didn’t expect humanity to ignore them when they warned of climate change, so their predictions were more conservative as they hoped we wouldn’t keep burning carbon at greater and greater rates as we are currently doing.

The key part though is ‘future rapid dynamical changes in ice flow’ which is scientist for big and unexpected changes, like the Arctic Death Spiral we had this summer where they found the Arctic was melting about 80 years ahead of schedule. The Arctic wasn’t supposed to be ice free in the summer from climate change until 2100, but we might get to see it as early as 2020.

What does that mean for future climate change projections? Well, it’s not pretty. So far the IPCC has been either seriously accurate (yay science!) or their worst case scenario underestimated what we’re actually doing to the planet. Which means that while the picture that the IPCC paints doesn’t look very appealing, it seems that reality could be a whole lot worse. My suggestion once again is that we stop burning carbon.

brisbane

Brisbane floods 2011 (photo: Eric Veland, flickr)

World Bank Wants off the Highway to Hell

“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. 

Getting off the Highway to Hell

Climate change is kicking in faster that expected, and the global threshold of 2oC is now considered the line between dangerous and extremely dangerous climate change. What will it take to avoid this highway to hell?

WHO: Kevin Anderson, Tyndall Centre for Climate Change Research, School of Mechanical, Aerospace and Civil Engineering, University of Manchester, UK  and School of Environmental Sciences and School of Development, University of East Anglia, Norwich, UK
Alice Bows, Sustainable Consumption Institute, School of Earth, Atmospheric and Environmental Sciences, University of Manchester, UK

WHAT: Some carbon budgetary truths for the world – how much do we have left to burn and when do we have to stop it by?

WHEN: 13 January 2011

WHERE: Philosophical Transactions of the Royal Society of London A: Mathematical, Physical and Engineering Sciences. Phil. Trans. R. Soc. A vol. 369, no. 1934

TITLE: Beyond ‘dangerous’ climate change: emission scenarios for a new world

Have you ever seen one of those reality TV shows where a person who is hopeless with money is given some budgeting ‘real talk’ and taught to live within their means? This paper is going to do that for your carbon budgets.

Humans love to procrastinate – we’re great at it. And despite all the new semester resolutions of keeping on top of the work this time, it inevitably leads to last minute late night exam cramming. However, it looks like climate change doesn’t have this problem. Currently, the arctic ‘death spiral’ is decades ahead of melting from climate change schedule, the Great Barrier Reef in Australia is already 50% bleached and dead and the drought predictions for the south west of the USA are also ahead of schedule.

This means that the globally declared point that we shall not pass for global warming of 2oC has now been upgraded from the line between acceptable and dangerous climate change to the border between dangerous and extremely dangerous climate change. Congratulations on the promotion 2oC?

So now that procrastinating past 2oC is looking like a dangerous decision, what do we need to do about it?

These researchers looked at the Copenhagen Accord from the 2009 UNFCCC negotiations (remember the non-binding one?) and it states that we must act to prevent going above 2oC of global warming on the basis of science and equity. Since it’s the cumulative emissions that are really going to bite us, the researchers decided to work from the end point of preventing 2oC in different scenarios and then worked the carbon budgets backwards to see if we have a chance of meeting the 2oC goal and how we could do it.

The UN separates the UNFCCC agreement into two groups: Annex 1 countries (which is the developed world) and non-Annex 1 countries (the developing world). Keeping with the ideal of equity, the scenarios in this paper allow for emissions to grow in the developing world longer than they can grow in the first world. However, the paper did point out that if developing nations grow into developed fossil fuel economies, their emissions will outstrip world emissions from the industrial revolution to the 1950s, so mitigation in the developing world is going to be increasingly important really fast.

The paper does three scenarios and then tweaks each one. The first scenario only counts CO2 emissions which allows it to be more accurate, but doesn’t include other greenhouse gases. The second scenario includes all six main greenhouse gases which makes it less accurate (more variables) but also more realistic. The third scenario looks at what is currently considered ‘politically possible’ in terms of emissions reductions. It gets long, so I’ll provide a handy summary table too!

Interestingly, the Bill McKibben budget of 565 Gigatonnes (Gt) of carbon (2055 Gt of CO2) from his Rolling Stone article is not considered here, because the chance of blowing past the 2oC limit is too high.

Here’s how they worked out:

CO2 only with a small budget
If we have a carbon budget of 1321 Gt CO2 and emissions from the developing world grow at less than 3% per year until 2015, and reduces by 6% per year after 2020, and the first world reduces their emissions from now by 11% per year, we have a 36% of still causing extremely dangerous climate change.

If we do the above but the developing world’s emissions grow until 2025, they’ve spent the whole carbon budget at once and we blow past 2oC. But if the developing world’s emissions grow at less than 1% until 2025 and they reduce their emissions by 7-8% per year while the first world reduces by 11% per year from now, then there’s a 37% chance of causing extremely dangerous climate change. The researchers described this one as ‘plausible but highly unlikely’.

CO2 with a small budget scenarios with a 36% chance (a), blowing the budget (b) and a 37% chance (c). Blue line is first world emissions, red line is developing world emissions, dotted line is global emissions including deforestation (from paper)

CO2 only with a bigger budget
So what happens if we’re a bit more realistic and increase the burnable budget a bit? If we have a carbon budget of 1578 Gt CO2 and emissions from the developing world grow by 4% per year until 2015, first world emissions don’t grow and global emissions reduce by 5-6% per year from 2015, we have a 50% chance of causing extremely dangerous climate change.

If there is a 5 year delay and emissions in the developing world grow by 4% per year until 2020, and then reduce by 7-8% per year after that while the first world reduces by 7-8% per year from 2010 (yes, from two years ago), then the 5 year delay bumps us up to a 52% chance of causing extremely dangerous climate change, even with the faster reductions. Given we needed to start two years ago, that one’s out too.

If the developing world misses the 7-8% per year reduction targets above and only reduce emissions by 4-5% per year, they spend all the carbon budget and we either blow past 2oC or first world emissions fall immediately to zero in 2015. Also not workable then.

CO2 with a bigger budget with a 50% chance (a), with a 52% chance (b) and blowing the budget (c) (from paper)

Counting all the gases with a small budget
If we include all the other greenhouse gases like methane and nitrous oxide (which means we start talking CO2 equivalent because otherwise it’s really unwieldy to count), we can also count emissions for food production for the 9 billion people we’re going to have on the planet by 2050, which will be around 6 Gt Co2e per year (animals fart methane and crops need nitrogen among other things) and further reduces the carbon budget.

If the budget is 1376 Gt CO2e and the developing world’s emissions grow at less than 3% per year until 2015, emissions in the first world need to drop to zero in 2015. So that budget is bust too.

All GHGs with a small budget which goes bust

Counting all the gases with a bigger budget
If the budget is 2202 Gt CO2e and the developing world increases emissions by less than 3% per year until 2015 and then decreases by 6% per year and the first world reduces emissions by 3% per year until 2020 and then 6% per year after that, we have a 39% chance of causing extremely dangerous climate change.

If the developing world grows at 3% per year until 2020 and then reduces emissions by 6% per year, the first world needs to reduce emissions by 10% per year from 2010. So that budget is also bust.

If the developing world only grows at 1% per year until 2025 and reduces by 4-5% per year, the first world’s emissions need to be flat to 2014 and reduce by 6% per year after that. If we could do that we would have a 38% chance of causing extremely dangerous climate change.

All GHGs with a bigger budget 39% chance left, busting budget middle, 38% chance right (from paper)

But here’s the problem; currently what is considered politically and economically possible for reducing carbon emissions is reductions of 3% per year. Which blows all of these budgets.

If we only counted the CO2,had a budget of 2741 GtCO2 (which is higher than any of the budgets above) and reduced our emissions by 3% per year from 2015 in the first world and 2030 in the developing world, we have an 88% chance of causing extremely dangerous climate change.

The politically feasible options counting CO2 left and all GHGs right, both with 88% chances of blowing 2oC (from paper)

If we counted all the gases and had a larger budget of 3662 Gt CO2e with reductions of 3% per year as above, we get the same result. This means that business as usual is actually business on the way to 4oC of global warming, which has been described by the one of the authors of this paper Kevin Anderson as

incompatible with organized global community, is likely to be beyond ‘adaptation’, is devastating to the majority of ecosystems & has a high probability of not being stable i.e.  4°C would be an interim temperature on the way to a much higher equilibrium level’

Scenarios in table form for quick reference (click for bigger version)

Basically, what we’re currently doing is going to fail spectacularly in the near future. And since physics doesn’t negotiate we can’t get an extension on this one. If we are to make any of the carbon budgets above, society needs to be reducing carbon emissions at a much higher rate than we currently are.

I’d like to finish with the conclusion from the paper, because I think their version of climate tough love is excellent:

This paper is not intended as a message of futility, but rather a bare and perhaps brutal assessment of where our ‘rose-tinted’ and well intentioned (though ultimately ineffective) approach to climate change has brought us. Real hope and opportunity, if it is to arise at all, will do so from a raw and dispassionate assessment of the scale of the challenge faced by the global community. This paper is intended as a small contribution to such a vision and future of hope.

Too Hot in Texas

New modelling of climate change effects on mosquito populations in the United States has surprising results – it might get too hot in summer even for the mosquitoes

WHO: R A Erickson, S M Presley, Department of Environmental Toxicology, and Institute of Environmental and Human Health, Texas Tech University, Lubbock, Texas
K Hayhoe, Department of Political Science, Texas Tech University, Lubbock, Texas
L J S Allen, Institute of Environmental and Human Health, and Department of Mathematics and Statistics, Texas Tech University, Lubbock, Texas
K R Long, Department of Mathematics and Statistics, Texas Tech University, Lubbock, Texas
S B Cox, Department of Environmental Toxicology, and Institute of Environmental and Human Health, Texas Tech University, Lubbock, Texas and Research and Testing Laboratory, LLC, Lubbock, Texas

WHAT: Population modelling for the Asian Tiger mosquito which carries dengue fever under two climate change scenarios

WHEN: 5 July 2012

WHERE: Environmental Research Letters, Vol. 7, No. 3 (July-Sept 2012)

TITLE: Potential impacts of climate change on the ecology of dengue and its mosquito vector the Asian tiger mosquito (Aedes albopictus)

This group of researchers in Texas decided it would be interesting to look at different climate change emissions scenarios from the IPCC and see what the effect of climate change might be on everybody’s ‘friend’ the Asian Tiger mosquito. For those of you who haven’t met the Asian Tiger mosquito, it is the type that carries dengue fever, which makes you very sick. So understandably, how climate change affects the population spread of this mosquito is pretty important.

The Asian Tiger mosquito is not your friend (Wikipedia)

The researchers looked at three localised areas in the US to run their model – Lubbock TX (where their University is), Atlanta GA, and to look at the potential geographical spread of the mosquito; Chicago IL.

Many of the predicted consequences of climate change are currently happening decades ahead of schedule, and one of the consequences is the expansion of the tropical belt by around 2- 4.8o latitude since 1979. This wasn’t expected to occur until 2100, so it means mosquitoes could be moving north faster than previously predicted.

The climate scenarios used were the A1FI (high emissions) and B1 (medium emissions) from the IPCC Special Report on Emissions Scenarios, which relate to approximately 970ppm (A1FI) and 550ppm (B1) of CO2 in the atmosphere. To give some context for those numbers, we’re currently sitting at 391ppm. 550ppm is where feedback loops have already kicked in and there are large ocean ‘dead zones’ where there’s not enough oxygen for plant and animal life. 970ppm is the IPCC’s ‘worst case scenario’ where there is mass biodiversity loss and a high likelihood of mass extinction events.

IPCC Emissions Scenarios A1FI (above) and B1 (below)

Anyway, back to mosquitoes. The researchers used three of the world’s best and most detailed climate models; the CM3 model from the UK’s Hadley Centre, the National Centre for Atmospheric Research model in Colorado, and the National Oceanic and Atmospheric Administration’s CM2.1 model. They used the mean temperature data from their three locations and combined it with the climate model to work out what the average temperatures might look like under the scenarios. Then they applied those conditions to mosquito populations to see what might change.

What they found was very interesting, and not what the researchers had originally expected. While the population size and duration of the mosquito season in Chicago increased across the board along with the potential dengue fever outbreak size, in Lubbock and Atlanta the mid-summer temperatures got too hot even for the mosquitoes.

Chicago (left) and Lubbock (right) with mid and end of century predictions. Chicago has an increase in mosquito population while Lubbock has a noticeable mid-summer die-off of mosquitoes (from paper)

While the mosquito season in Lubbock started earlier and had a potential for greater dengue fever outbreaks, the super-hot summer temperatures under both of the climate change scenarios modelled led to mosquitoes dying and a reduction in potential dengue fever outbreaks. This could have many social and health policy ramifications in the areas studied and also shows that the local level effects of climate change may manifest in ways we haven’t previously thought of.

Humans are notoriously difficult to predict and we don’t know yet what humanity will do about climate change in the near future. This gets combined with natural systems and feedbacks that are highly integrated and complex which means one seemingly unrelated process may be triggered in another previously unrelated process.

However, complexity doesn’t mean that models aren’t relevant or useful and the proverbial baby should be thrown out with the bathwater. Models give us a range of possibilities to plan for and allow humans the opportunity to act in our own long term best interests.

Currently, we’re not acting for our long term well being, and humanity is currently burning carbon at a rate that matches or beats the A1FI high emissions scenario that very probably leads to mass extinction, including humans. Which means that now would be the time to stop burning fossil fuels. Before Texas becomes so scorching hot that even the mosquitoes die from the mid-summer heat.

Predicting the Unpredictable: Tropical Hydrology

Unpredictable tropical storms from climate change and changing land-use patterns are going to mess with water cycles

WHO:  Ellen Wohl (Department of Geosciences, Colorado State University, Fort Collins, Colorado)
Ana Barros (Duke University, Pratt School of Engineering, Durham, North Carolina)
Nathaniel Brunsell (Department of Geography, University of Kansas, Lawrence, Kansas)
Nick A. Chappell (Lancaster Environment Centre, Lancaster University, Lancaster, UK)
Michael Coe (Woods Hole Research Center, Falmouth, Massachusetts )
Thomas Giambelluca (Department of Geography, University of Hawaii at Manoa, Honolulu, Hawaii )
Steven Goldsmith (Department of Geography and the Environment, Villanova University, Villanova, Pennsylvania)
Russell Harmon (Environmental Sciences Division, ARL Army Research Office, North Carolina)
Jan M. H. Hendrick (New Mexico Institute of Mining and Technology, Socorro, New Mexico)
James Juvik (Department of Geography and Environmental Studies, University of Hawaii-Hilo, Hilo, Hawaii)
Jeffrey McDonnell (Department of Forest Engineering, Resources, and Management, Oregon State University, Corvallis, Oregon)
Fred Ogden (Department of Civil and Architectural Engineering, University of Wyoming, Laramie, Wyoming)

WHAT: Looking at what we know about tropical water patterns and working out what we don’t know

WHEN: September 2012

WHERE: Nature Climate Change, Vol 2 Issue 9, September 2012

TITLE:  The hydrology of the humid tropics (subs. req)

This paper from Nature Climate Change does two things; it looks at what we know about tropical water cycles (hydrology) and also the gaps in our knowledge (scientists- always wanting to know more!).

So what do we know?

Firstly, let’s define the ‘tropics’. This paper looks specifically at the humid tropics which is anywhere that precipitation exceeds evaporation 270 days a year or more, and is generally 25⁰ latitude either side of the equator.

The tropics highlighted in red (Wikipedia)

Fun fact – the tropics is where the term ‘the doldrums’ comes from. It’s officially known as the ‘Intertropical Convergence Zone’ and is the area where the winds coming from the northern hemisphere and the southern hemisphere collide, creating erratic weather patterns and violent thunderstorms. This poses a few issues in the face of climate change. Climate change will make weather more extreme and the effects will be non-linear, so this means the tropics are about to get even less easy to predict.

There are many areas of the tropics where land-use changes are affecting water cycles. Deforested areas outnumber the remaining forest, which is already having a measurable effect on rain patterns in Brazil; extending the dry season and rain being more intense when it does occur. It’s estimated that deforestation in the South Eastern Amazon has increased the flow of water to the ocean by 20% in the last 40 years. These changes and others will likely be amplified with increased climate change effects.

Billions of people rely on the major rivers in the tropics for their fresh water, and flows of water, energy and carbon are all closely linked to the amount and age of vegetation in the area. Changes in water flows and rain patterns can be disastrous, and can occur from combinations of land-use change, deforestation and climate change. So messing with the systems can create large changes. The closely linked relationship between vegetation type and water cycles also means that my idea of trying to grow an Australian gum tree here in Vancouver when I feel homesick is a bad one.

However, while water cycles are being modified across the tropics by land-use changes, deforestation and climate change, the effects are going to vary region by region, making predictions difficult. There are far fewer weather measuring stations in tropical areas than temperate areas, so less data overall. The researchers identified moisture cycling, water catchment processes and long term data collection as areas that need improvement if we are going to be able to accurately predict global warming changes in the tropics.

Number of weather stations in temperate vs tropical areas (from paper)

In order to answer important questions that relate to the availability of fresh water for billions of people and extreme weather in areas that have earthquake activity as well as cyclones there needs to be a detailed body of data. Forewarned is forearmed, especially if systems are heading towards possible tipping points, and this paper would like researchers to study more tropical areas to better understand them.

Busting our Carbon Budget: Siberian Permafrost

Siberian permafrost is releasing ancient carbon much faster than previously thought

WHO: J. E. Vonk, L. Sánchez-García, B. E. van Dongen, V. Alling, A. Andersson, Ö. Gustafsson (Department of Applied Environmental Science (ITM) and the Bert Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden)
D. Kosmach, A. Charkin, O. V. Dudarev (Pacific Oceanological Institute, Russian Academy of Sciences, Vladivostok, Russia)
I. P. Semiletov, N. Shakhova (Pacific Oceanological Institute, Russian Academy of Sciences, Vladivostok, Russia and International Arctic Research Center, University of Alaska, Fairbanks, Alaska)
P. Roos (Risø National Laboratory for Sustainable Energy, Roskilde, Denmark)
T. I. Eglinton (Geological Institute, ETH-Zürich, Zürich, Switzerland)

WHAT: Measuring and calculating the carbon released from thawing and eroding permafrost in far northern Russia

WHEN: 6 September 2012

WHERE: Nature, Vol 489, 137-140

TITLE: Activation of old carbon by erosion of coastal and subsea permafrost in Arctic Siberia (subs req.)

Those of you who read the recent Bill McKibben article in Rolling Stone magazine about the planet’s atmospheric carbon budget will know ~565 Gigatonnes is the amount of carbon pollution that humans can still burn and hope to avoid catastrophic climate change. Beyond that, we’re playing Russian roulette with extra bullets loaded.

Why am I talking about Rolling Stone when this paper is talking about Siberia? Well, the researchers for this paper went to far northern Russia to work out how much coastal Siberian permafrost is being eroded away, releasing the carbon into the atmosphere and spending our ever shrinking carbon budget.

Muostakh Island (point A, Google maps)

The Arctic permafrost in Siberia holds ~1,000 Gigatonnes of carbon frozen on land, ~400 Gigatonnes of coastal carbon and ~1,400 Gigatonnes of sub-sea carbon. So if this permafrost starts thawing and releasing carbon at a great rate, we humans have totally bust our carbon budget and the future is looking pretty horrifying; much like the greenhouse extinction from last week’s post.

So is it thawing out? And how fast?

The Island of Muostakh in the north of Russia has been eroding at a rate of up to 20m per year, and this is where the researchers went to try and measure the amount of carbon that is being released into the atmosphere.

Eroding cliffs on Muostakh Island (from paper)

They used a dual carbon-isotope mixing model solved with a Monte Carlo simulation strategy, which is sadly not a really tasty sounding desert, but a way of working out which carbon isotopes are from plankton, topsoil or old carbon which is the stuff they’re interested in (they used 13C and 14C isotopes for those playing at home).

Through the isotope analysis they found a coastal permafrost carbon release of 22 Megatonnes (.022 Gigatonnes) of carbon per year from erosion. Additionally they estimate that 66% of the old carbon that is washed into the ocean degrades downstream and is released into the atmosphere instead of sinking to the sea floor. Previous research had thought that carbon from coastal erosion washed into the ocean without releasing into the atmosphere.

Once you combine the carbon eroded with the 66% downstream degradation, the total atmospheric release is 44 Megatonnes (.044 Gigatonnes) of carbon per year which is much larger than the previously estimated 4 Megatonnes of carbon per year. This large difference may be because of methods used in previous research, unaccounted for changes in coastal elevation (the higher the cliff, the harder for the waves to reach it) or not counting the sub-sea degradation.

Either way, the idea that we may be under-counting the amount of carbon released from thawing and eroding Siberian permafrost has some serious implications for all of us. We are currently polluting the atmosphere with carbon at a rate of 31.6 Gigatonnes per year and rising. As we continue to burn carbon, the permafrost in Siberia will thaw and erode faster, increasing from the current rate of .044 Gigatonnes per year.

We are quickly running out of time and atmospheric space to stop runaway climate change. If even half the sub-sea permafrost is released as atmospheric carbon, we’ve surpassed 565 Gigatonnes. Hopefully the increased and continued thawing of the Siberian permafrost isn’t the bit that busts our carbon budget.