The big crunch

By Gareth Renowden 

The Daily Blog, May 29, 2013  

The evidence that humans are damaging their ecological life-support systems is overwhelming based on the best scientific information available, human quality of life will suffer substantial degradation by 2050 if we continue on our current path.

Climate change is not the only problem our civilisation has to sort out in the next few decades. If we're going to provide fulfilling lives and a decent standard of living for all the nine billion people expected to be alive by the middle of the century, we're going to have to learn to live within a set of planetary boundaries. Last week, an international group of scientists and academics calling themselves the Millennium Alliance for Humanity & the Biosphere (MAHB) launched an appeal to world leaders for urgent coordinated action in five key areas — climate disruption, extinctions, loss of ecosystem diversity, pollution, and human population growth and resource consumption.

Their message is stark:

…the evidence that humans are damaging their ecological life-support systems is overwhelming […] based on the best scientific information available, human quality of life will suffer substantial degradation by 2050 if we continue on our current path.

…And:

By the time today's children reach middle age, it is extremely likely that Earth's life-support systems, critical for human prosperity and existence, will be irretrievably damaged by the magnitude, global extent, and combination of these human-caused environmental stressors, unless we take concrete, immediate actions to ensure a sustainable, high-quality future.

MAHB's message, contained in a document titled Scientific Consensus on Maintaining Humanity's Life Support Systems in the 21st Century: Information for Policy Makers (pdf, Page 3, Essential points for Policy Makers, attached below), makes for depressing reading. We're well on the way to stuffing up the planet's climate, we're causing species extinctions at a rate not seen since an asteroid hit the planet 65 million years ago and wiped out the dinosaurs, we've transformed 40% of the ice-free land on the planet through farming, logging and building towns and cities, we're polluting the atmosphere and oceans, and population and resource consumption are growing fast.

All of these impacts feed on each other, and make it more likely that the planet will pass through tipping points that lead to irreversible changes. It's not enough to work on just one issue — we have to work on all of them at the same time, and quickly. The longer we leave it, the more expensive and difficult it will be to prevent crisis turning into disaster. "Delaying even a decade may be too late," the statement warns.

This is a huge challenge for the political process around the world. Progress on climate change — a problem first identified in the 1980s — has been pitifully slow. Economic and political inertia, exploited by industries that stand to lose if carbon emissions are cut, have made meaningful international action all but impossible to achieve. Thirty years of fine talk and empty promises mean that we're now staring down the barrel of irreversible and highly damaging climate change.

It's difficult to be optimistic that the world is suddenly going to sit up and pay attention. There's too much money to be made, and influence to be bought, by carrying on with business as usual. Ultimately the planet will find a way to deal with humanity's impacts if we don't, and the outcome is unlikely to be pretty.

Uncertainty no excuse for procrastinating on climate change

Roger Bodman, Postdoctoral Research Fellow,  Centre for Strategic Economic Studies at Victoria University,  

David Karoly, Professor of Climate Science at University of Melbourne

The Conversation, 27 May 2013

Today we released research which reduces the range of uncertainty in future global warming. It does not alter the fact we will never be certain about how, exactly, the climate will change.

We always have to make decisions when there are uncertainties about the future: whether to take an umbrella when we go outside, how much to spend on insurance. International action on climate change is just one more decision that has to be made in an environment of uncertainty.

The most recent assessment of climate change made by the Intergovernmental Panel on Climate Change in 2007 looked at what is known with high confidence about climate change, as well as uncertainties. It included projections of future global warming to the end of this century based on simulations from a group of complex climate models.

These models included a range of uncertainties, coming from natural variability of the climate and the representation of important processes in the models. But the models did not consider uncertainty from interactions with the carbon cycle – the way carbon is absorbed and released by oceans, plant life and soil. In order to allow for these uncertainties, the likely range of temperature change was expanded.

Our recent study has re-visited these results and tested an approach to reduce the range of uncertainty for future global warming. We wanted to calibrate the key climate and carbon cycle parameters in a simple climate model using historical data as a basis for future projections. We used observations of atmospheric carbon dioxide concentrations for the last 50 years to constrain the representation of the carbon cycle in the model. We also took the more common approach of using global atmospheric and ocean temperature variations to constrain the response of the climate system.

This led to a narrower range of projected temperature changes for a given set of greenhouse gas emissions. As a consequence, we have higher confidence in the projections. In other words, using both climate and carbon dioxide observations reduces the uncertainties in projections of global warming.

We found that uncertainties in the carbon cycle are the second-largest contributor to the overall range of uncertainty in future global warming. The main contributor is climate sensitivity, a measure of how the climate responds to increases in greenhouse-gas concentrations.

Climate sensitivity has been discussed recently on The Conversation. A recent study by Alexander Otto of Oxford University and colleagues, published in the journal Nature Geoscience, also considered future global warming in the context of observations of global mean temperature change over the last decade.

Unlike that study, our results do not show lower climate sensitivity or lower mean projected global warming. Our study uses the same observed global atmospheric and ocean temperature data. But we also used observed carbon dioxide data and represented important additional processes in our simplified climate model, particularly the carbon cycle on the land and in the ocean and uncertainties in the climate forcing due to aerosols.

In our study, the reductions in uncertainty came from using the observations, the relationships between them and how these affect the parameters in the simple climate model. We found 63% of the uncertainty in projected warming was due to single sources, such as climate sensitivity, the carbon cycle components and the cooling effect of aerosols, while 37% of uncertainty came from the combination of these sources.

Once we reduced the uncertainty we found there is an increased risk of exceeding a lower temperature change threshold, but a reduced chance of exceeding a high threshold. That is, for business-as-usual emissions of greenhouse gases, exceeding 6°C global warming by 2100 is now unlikely, while exceeding 2°C is virtually certain.

These results reconfirm the need for urgent and substantial reductions in greenhouse gas emissions if the world is to avoid exceeding the global warming target of 2°C. Keeping warming below 2°C is necessary to minimise dangerous climate change.

It is unlikely that uncertainties in projected warming will be reduced substantially. Indeed, if you allow for population growth, levels of economic activity, growth in demand for energy and the means of producing that energy, overall uncertainty increases. We just have to accept that we will have to manage the risks of global warming with the knowledge we have. We may not know exactly how much and by when average temperatures change, but we know they will. This is an experiment we probably don't want to make with the only planet we have to live on.

Trenberth: Global Warming Is Here To Stay, Whichever Way You Look At It

 The Conversation, 23 May 2013

by Kevin Trenberth 

Has global warming stalled? This question is increasingly being asked because the local weather seems cool and wet, or because the global mean temperature is not increasing at its earlier rate or the long-term rate expected from climate model projections.

The answer depends a lot on what one means by "global warming." For some it is equated to the "global mean temperature." That keeps going up but also has ups and downs from year to year. More on that shortly.

Why should it go up? Well, because the planet is warming as a result of human activities. With increasing carbon dioxide and other heat-trapping greenhouse gases in the atmosphere, there is an imbalance in energy flows in and out of the top of the atmosphere: the greenhouse gases increasingly trap more radiation and hence create warming. "Warming" really means heating, and this can exhibit itself in many ways.

Rising surface temperatures are just one manifestation. Melting Arctic sea ice is another. So is melting of glaciers and other land ice that contribute to rising sea levels. Increasing the water cycle and invigorating storms is yet another. But most (more than 90%) of the energy imbalance goes into the ocean, and several analyses have now shown this. But even there, how much warms the upper layers of the ocean, as opposed to how much penetrates deeper into the ocean where it may not have much immediate influence, is a key issue.

The ups and downs of global temperature

My colleagues and I have just published a new analysis showing that in the past decade about 30% of the heat has been dumped at levels below 700m, where most previous analyses stop.

The first point is that this is fairly new; it is not there throughout the record. The cause of the shift is a particular change in winds, especially in the Pacific Ocean where the subtropical trade winds have become noticeably stronger, changing ocean currents and providing a mechanism for heat to be carried down into the ocean. This is associated with weather patterns in the Pacific, which are in turn related to the La Niña phase of the El Niño phenomenon.

The second point is that we have found distinctive variations in global warming with El Niño. A mini global warming, in the sense of a global temperature increase, occurs in the latter stages of an El Niño event, as heat comes out of the ocean and warms the atmosphere. The ocean's temperature is also affected by volcanic eruptions, which also affect the perceptions of global warming.

Normal weather also interferes by generating clouds that reflect the sunshine, and there are fluctuations in the global energy imbalance from month to month. But these average out over a year or so.

Another prominent source of natural variability in the Earth's energy imbalance is changes in the sun itself, seen most clearly as the sunspot cycle. From 2005 to 2010 the sun went into a quiet phase and the warming energy imbalance is estimated to have dropped by about 10 to 15%.

Some of the penetration of heat into the depths of the ocean is reversible, as it comes back in the next El Niño. But a lot is not; instead it contributes to the overall warming of the deep ocean. This means less short-term warming at the surface, but at the expense of greater long-term warming, and faster sea level rise. So this has consequences.

Global warming is here to stay

Coming back to the global temperature record, one thing is clear. The past decade is by far the warmest on record. Human induced global warming really kicked in during the 1970s, and warming has been pretty steady since then….

Focusing on the wiggles and ignoring the bigger picture of unabated warming is foolhardy, but an approach promoted by climate change deniers. Global sea level keeps marching up at a rate of more than 30cm per century since 1992 (when global measurements via altimetry on satellites were made possible), and that is perhaps a better indicator that global warming continues unabated. Sea level rise comes from both the melting of land ice, thus adding more water to the ocean, plus the warming and thus expanding ocean itself.

Global warming is manifested in a number of ways, and there is a continuing radiative imbalance at the top of atmosphere. The current hiatus in surface warming is temporary, and global warming has not gone away.

–  Kevin Trenberth is Distinguished Senior Scientist at University Corporation for Atmospheric Research. Reposted with permission from the author.

Blowing the carbon budget

John Kemp

The Age, May 18, 2013 

Budgets are made to be broken - especially when they are written by politicians.

Unfortunately it seems the world is on course to break the carbon budget that scientists and policymakers agree is necessary to limit the rise in global temperatures to less than 2 degrees Celsius.

If governments were really committed to limiting the rise in temperatures to 2 degrees, two-thirds of the currently known oil, coal and gas reserves would have to be left in the ground, according to the International Energy Agency (IEA).

But it is not clear anyone is taking the target seriously. In the last 12 months, the top 200 oil, gas and mining companies allocated up to $US674 billion to finding and developing even more reserves, according to the Climate Tracker Initiative.

The shares of petroleum and mining companies listed on New York, London and other stock exchanges value them as if all these resources will be extracted and burned.

There is a "gross inconsistency between current valuations for fossil fuel assets and the path governments have committed to take", according to Nicholas Stern, a leading adviser to Britain's government on the economics of climate change.

Total carbon budget

In 2010, countries in the United Nations Framework Convention on Climate Change confirmed their intention to limit emissions of greenhouse gases to hold the rise in average temperatures to less than 2 degrees above pre-industrial levels.

Two degrees is "considered the threshold for preventing dangerous anthropogenic interference with the climate system", the IEA wrote in its "2012 World Energy Outlook".

Limiting warming to 2 degrees with a probability of 50 per cent implies the atmospheric concentration of greenhouse gases must be stabilised at about 450 parts per million of carbon dioxide (CO2) equivalent, according to the IEA and scientific advisers on the Intergovernmental Panel on Climate Change (IPCC).

The 450 parts per million target implies there is a maximum amount of carbon dioxide that can be emitted and of fossil fuels that can be burned - something both policymakers and climate campaigners have termed the global "carbon budget".

"Carbon dioxide emissions from fossil fuels and land-use change in the first half of this century must be kept below 1,440 billion tonnes of CO2 equivalent," according to the IEA.

"Since a total of 420 billion tonnes of CO2 have already been emitted between 2000 and 2011, and we estimate that 136 billion tonnes will be emitted from non-energy related sources in the period up to 2050, a maximum of 884 billion tonnes can be emitted by the energy sector from 2012 to 2050," the IEA concluded.

Climate campaigners have come up with similar estimates. "The available budget is 900 billion tonnes of CO2 for an 80 per cent probability to stay below 2 degrees and 1,075 billion tonnes for a 50 per cent probability," according to the Carbon Tracker Initiative's report "Unburnable Carbon 2013: wasted capital and stranded assets".

Given the substantial amount of uncertainty surrounding the measurement of emissions and their precise impact on temperatures, it is safe to assume the carbon budget is around 1,000 billion tonnes of CO2 equivalent between now and 2050.

Energy-related CO2 emissions were just over 31 billion tonnes in 2011 and rising, IEA figures show.

Cooking the planet

There are more than enough fossil fuels to cook the planet many times over. Current proven and probable reserves of oil, gas and coal (resources which have been found and are estimated with a probability of more than 90 per cent and 50 per cent respectively) would emit the equivalent of 2,860 billion tonnes of CO2 if they are all burned, according to the IEA.

"More than two-thirds of current ... fossil fuel reserves cannot be commercialised in a 2 degree world before 2050," IEA cautions.

Nicholas Stern explains in a forward to the "Unburnable carbon 2013" report: "If we burn all current reserves of fossil fuels, we will emit enough CO2 to create a prehistoric climate, with Earth's temperature elevated to levels not experienced for millions of years.

"Smart investors can already see that most fossil fuel reserves are essentially unburnable ... They can see that investing in companies solely or heavily relying on constantly replenishing reserves of fossil fuels is becoming a very risky decision," Stern claims.

The facts suggest otherwise. "The markets appear unable to factor in the long-term shift to a low-carbon economy into valuations and capital allocation," the Climate Tracker Initiative admits. "Capital needs to be redirected away from high-carbon options."

"The bulk of (the $US674 billion investment) was derived from retaining earnings - pointing to the duty of shareholders to exercise stewardship over these funds so they are deployed on financially gainful opportunities consistent with climate security.

"The current balance between funds being returned to shareholders, capital invested in low-carbon opportunities and capital used to develop more reserves needs to change," Climate Tracker Initiative argues.

Investment boycott

"Unburnable carbon 2013" sets out recommendations for finance ministers, regulators, actuaries, advisers and investors to help force a re-evaluation of the risks of investing in more fossil fuel production and to push capital towards lower-carbon alternatives.

Bill McKibbin's 350.org is mobilising a grass-roots campaign to convince pension funds investing on behalf of state, municipal and college employees in the United States to divest their holdings in fossil fuel companies. The aim is to force change by organising an investment boycott similar to those mounted against South Africa during apartheid, and more recently against Iran.

350.org demands fossil fuel companies stop exploring for new hydrocarbons, stop lobbying in Washington and state capitols, and "pledge to keep 80 per cent of their current reserves underground forever".

Is anyone listening?

So far, the concepts of a carbon budget and of a maximum amount of fossil fuels that can be burned have not got much traction with policymakers, corporations or the public.

Earlier this month, the average daily concentration of greenhouse gases measured at the Mauna Loa Observatory in Hawaii passed 400 parts per million. It is rising at about 2 parts per million every year, yet the milestone generated comparatively little comment and relative indifference from the public and officials.

Voters and politicians seem unconvinced that the 450 ppm target can or should be achieved.

"Collectively, humanity has yawned and decided to let the dangers mount," columnist Martin Wolf observed in the Financial Times on Monday ("Why the world faces climate chaos" May 15).

"We will watch the rise in greenhouse gases until it is too late to do anything about it," he concluded

Wolf went on to explain the seven reasons for inaction and speculate on what would be necessary to spark a real effort to change.

Apocalyptic warnings about the dangers will not work, he said. If action is required, they must be replaced by a much more positive vision of a prosperous and low-carbon future.

In the meantime, "there is no political will to do anything real about the process driving our experiment with the climate. Yes there is talk and wringing of hands. But there is, predictably, no effective action," he notes sadly.

Campaigners such as 350.org and the Climate Tracker Initiative hope to change that indifference by pushing the issue back up the agenda.

Investors and fossil fuel companies are gambling that they will not succeed, and politicians are not serious about enforcing a combustion cap.

(John Kemp is a Reuters market analyst. The views expressed are his own)

Reuters

As carbon dioxide hits a new high, there’s still no Planet B

Andrew Glikson, Earth and paleo-climate scientist at Australian National University

The Conversation, 13 May 2013, 2.35pm

For the full article, with figures mentioned in the text, click the link 

On May 9, 2013, the National Oceanic and Atmospheric Administration in the US recorded CO₂ levels in the atmosphere at of 400 parts per million. This signifies a return to the atmospheric conditions similar to those of the Pliocene, which ended about 2.6 million years ago.

The tropical Pliocene

Global Pliocene temperatures were on average about 2–4°C warmer than pre-industrial temperatures. Those temperatures drove an intense hydrological cycle with extreme evaporation and precipitation. It led to extensive rain forests, lush savannas (now occupied by deserts), small ice caps (about two-thirds of the present) and sea levels about 25 meters higher than at present.

Life abounded during the Pliocene. But such conditions mean agriculture would hardly be possible. The tropical Pliocene had intense alternating downpours and heat waves. Regular river flow and temperate Mediterranean-type climates which allow extensive farming could hardly exist under those conditions.

After the Pliocene, the Earth's climate shifted gradually into the Pleistocene. During the following 2 million years, glacial-interglacial periods required species to adapt to rapid climate shifts. These shifts included abrupt warming events actually within glacial periods, where regional warming by several degrees occurred over periods as short as several decades to a century.

Basic physics and chemistry, as well as the geological record, tell us that greenhouse gases are the key factor determining the current climate trend. Current greenhouse gas rise rates exceed those of the Pleistocene cycles by more than an order of magnitude. These rates, which during 2012-2013 reached 2.89 ppm CO₂ per year, exceeding any recorded for the last 65 million years, would hardly allow species to adapt to changing climate conditions (see Figure 1).

Will this mean mass extinction?

The current CO₂ ppm per year rise rate surpasses CO₂ and temperature rise rates during mass extinctions about 55 million years ago and 65 million years ago.

Fifty-five million years ago, large-scale release of methane drove atmospheric CO₂ to near-1800 ppm and temperature rise to about 5°C over a period of 10,000 years. (That's 0.18 ppm CO₂year and 0.0005°C/year.)

Sixty-five million years ago, the K-T asteroid impact resulted in a rise of more than 2000ppm CO₂ and about 7.5°C over a period of about 10,000 years (or about 0.2 ppm/year and 0.00075°C per year). About 4500 billion tons of carbon was released from impacted carbonates and shale, from ignited bushfires and from ocean warming. The CO₂ rise rate was an order of magnitude lower than current rate of 3ppm/year.

What will the world look like?

The current rise in greenhouse gases is enhancing the hydrological cycle, with ensuing floods, heat waves and droughts.

If we burned all the Earth's known fossil fuel reserves it would lead to atmospheric CO₂ levels of around 800 to 1000ppm, high or total melting of the polar ice caps, sea level rise on the scale of tens of meters and disruption of the biosphere on a scale analogous to recorded mass extinctions.

At the same time as CO₂ emissions, sulphur dioxide (SO₂) is being released, mainly from coal burning. This sulphur is increasing the reflection of the atmosphere and thus regulates changes in temperature, as shown in Figure 2 for the periods following 1950, 1975 and 2001. The trend of rising temperatures slowed in 1950 and 2001 when sulphur emissions increased. Likewise, when clean air policies were introduced in 1975, slowing sulphur emissions, a fast-rising temperature trend resumed. The current rise in coal burning and sulphur emissions are locking the world into a Catch-22 cycle.

Carbon emissions may be self-limiting. It is likely that, before atmospheric CO₂ reaches 500ppm, extreme weather events would disrupt industrial and transport fossil fuel-combusting systems enough to lead to reduction of emissions. However, the feedback processes like methane release, forest bushfires and warming oceans will drive CO₂ levels further.

When will we act?

The land, oceans and biosphere are now in extreme danger, but it doesn't seem to be driving the global community to the urgent measures required for a meaningful attempt to arrest the current trend. With few exceptions, the accelerating rate of atmospheric CO₂ hardly rates a mention on the pages of the global media, preoccupied as it is with short-term economic forecast, daily exchange rates, share market fluctuations and sports results.

In Australia the language has changed from "the greatest moral issue of our generation" to controversy over a "carbon tax", diverting the public attention from the climate to a hip-pocket nerve. While we debate the ways to bring about a meaningless 5% reduction in local emissions, we simultaneously develop infrastructure to export hundreds of millions of tons of coal. It all ends up in the same atmosphere.

As Carl Sagan reminded us, on seeing a photograph of Earth taken from Voyager 1 as it left the Solar System

That's here. That's home. That's us. On it everyone you know, everyone you love, everyone you've ever heard of, every human being who ever was, lived out their lives … Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity — in all this vastness — there is no hint that help will come from elsewhere to save us from ourselves.

Habitats to shrink without carbon curbs: Nature

The Age, May 13, 2013   

The habitats of many common plants and animals will shrink dramatically this century unless governments act quickly to cut rising greenhouse gas emissions, scientists said on Sunday after studying 50,000 species around the world.

The scientists from Britain, Australia and Colombia said plants, amphibians and reptiles were most vulnerable as global temperatures rise and rainfall patterns change.

About 57 per cent of plants and 34 per cent of animal species were likely to lose more than half the area with a climate suited to them by the 2080s if nothing was done to limit emissions from power plants, factories and vehicles, they wrote in the journal Nature Climate Change.

Hardest hit would be species in sub-Saharan Africa, Australia, the Amazon and Central America.

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"Climate change will greatly reduce biodiversity, even for many common animals and plants," lead author Rachel Warren of the University of East Anglia in England said. The decline would damage natural services for humans such as water purification and pollination, she said.

But the scientists said governments could reduce the projected habitat loss by 60 per cent if global greenhouse gas emissions peaked by 2016 and then fell. A peak by 2030 would cut losses by 40 per cent.

Only 4 per cent of animals, and no plants, were likely to benefit from rising temperatures and gain at least 50 per cent extra territory, the study said.

However, some experts said while it was clear that global temperatures were rising, forecasting the effect on plants and animals was often unreliable as species range was difficult to check.

Difficult balance

Some past studies have indicated that creatures such as bats, hares or opossums may be more able to adapt to new climates than believed. Yet many species of frogs and toads are suffering worse declines in numbers than projected by computer models, apparently because a fungal skin disease is aggravating the effects of global warming.

"It's very difficult to get the right balance between crying wolf and examining the facts," said Carsten Dormann, professor at the Helmholtz Centre for Environmental Research in Germany, who was not involved in the study. "We simply don't know if these assessments are correct."

The scientists said: "Over half of common plants and one third of the animals could see a dramatic decline this century due to climate change." They said their findings were "probably conservative" as they did not take account of factors that could exacerbate declines, such as pests or diseases.

Almost 200 governments have agreed to limit global warming to less than 2 degrees C (3.6F) above pre-industrial times. They plan to agree, by the end of 2015, a deal to curb emissions.

Global average surface temperatures have risen by 0.8 degree C (1.4F) since the Industrial Revolution.

The amount of carbon dioxide, a greenhouse gas, in the atmosphere topped 400 parts per million for the first time since measurements began in 1958, the U.S. National Oceanic and Atmospheric Administration said on Friday.

A U.N. panel of climate scientists says it is at least 90 per cent likely that human activities, rather than natural variations, are the main cause of warming since about 1950.

Reuters