Climate Feedback

Climate scientists, weather forecasters and policy makers are gathered in Geneva this week to discuss the need for reliable climate predictions to help society adapt to climate change.

The third World Climate Conference of the World Meteorological Organization, which runs from 31 August to 4 September 2009, aims to produce a new global framework for delivering climate information to end users.

Scientists at the conference are hopeful that with sustained support for climate research and improved computing capabilities they could reliably predict climate impacts at much higher resolution – perhaps down to several tens of kilometres over the coming decades. The ultimate goal , and one that was voiced at last year’s World Climate Modelling Summit in Reading (which we covered here) is to produce climate predictions that are as reliable and useable as weather forecasts.

That would be a vast improvement on the projections available from today’s global climate models. Most of these enable estimates of how temperature, and other climate variables such as rainfall, will change over areas of several hundred kilometres up until the end of the century and beyond.

While a large focus of the conference is on improving climate modelling in order to make reliable predictions, delegates in Geneva are also discussing the need to tailor information to the needs of specific end-users.

“A forecast in not enough; our challenge is to communicate what we know that the future in a manner that can allow people to make decisions”, said Gro Harlem Brundtland, special envoy of the UN secretary-general on climate change, at the opening session on Monday. At the end of the 5-day conference, delegates will issue a declaration of their intent to establish a new global framework to meet this challenge.

But major advances will be needed in the science of prediction before climate information is of real service to society. “In 10-15 years we may have climate forecasts like we now have weather forecasts”, said Guy Brasseur of the National Centre for Atmospheric Research (NCAR) in Boulder, Colorado to delegates here on Monday. “We have the international vision, expertise and scientific commitment to deliver climate services”, said Brasseur, but he also warned of the difficulties in developing climate models of sufficiently high spatial resolution and reliability.

One hurdle is the massive investment needed to fund one or more supercomputers; others include accessing data and sustaining long-term observations. Despite these, several attempts to improve predictive capability are underway worldwide. One of these, being championed by Tim Palmer of the European Centre for Medium-Range Weather Forecasts is the concept of ‘seamless prediction’, in which one modelling system is used to predict atmospheric conditions on time scales varying from hours to decades. Other efforts, being headed by scientists from the UK Met Office and elsewhere, are focused on how climate change will pan out in the coming decades, and combines aspects of seasonal forecasting with centennial prediction (which I won’t go into now, but hope to come back to). Still another approach is Earth System Modelling, which attempts to model the whole earth system – including feedbacks - more comprehensively than climate models, at spatial scales of 150km across.

Scientists at the conference are excited at the possibility that such efforts will lead to greater predictability, but are also concerned that end-users could have unrealistic expectations of what that means. “We’ll never be able to produce absolute predictions of what will happen in the future”, says Vicky Pope of the UK Met office. She says that scientists must work within a risk management framework so that people don’t misuse the data. “We are nervous about the uncertainties and errors associated with the models we are using”, says Jerry Meehl of NCAR, adding “That needs to be part of the message that gets out with climate services”.

Olive Heffernan

Posted by Olive Heffernan on September 01, 2009
Categories: Climate prediction, Communicating Climate Change, Olive Heffernan, Regional climate, WCC-3 | Permalink | Comments (0) | TrackBacks (0)

Long-awaited projections of how climate change will impact the UK have been met with caution by scientists.

The projections, released yesterday in London, offer the most detailed picture yet of how the UK - piece by piece, in sections just 25 km sq - will be affected by various climate impacts.

Their main message is that without substantial efforts to cut global greenhouse gas emissions, Britons could be in for a hard time by the 2080s. While the risk of flooding will worsen in the North West, the South East will face an anticipated 22% decline in summer rainfall. If emissions continue to rise, London will likely experience a 2-6°C degree rise in temperature and sea-level rise of 36cm.

The UK government hopes the information will enable citizens and local authorities adapt to the changes that lie ahead, but some fear the projections provide misleading information.

That’s because the method used to produce these highly detailed projections of the future is new – and hasn’t yet been through peer-review. Bob Watson, chief scientist with the UK Department of the Environment Food and Rural Affairs (DEFRA) is confident it’s just a matter of time before the methodology is used on a broader scale. He expects it “will be taken up by other regions and highlighted by the IPCC in their next report”.

But while the projections were originally slated for release last November, an independent committee was convened at the eleventh hour to check out the methodology.

Oxford climatologist Myles Allen was on the committee, and he’s concerned that the results stretch the science beyond its current capabilities. His main worry is that as recently as 2007, the Intergovernmental Panel on Climate Change didn’t think that climate variables could be reliably resolved at spatial scales beyond a couple of 1000kms. And no research published since has challenged that view.

He spoke to me about this for Nature News, where I’ve covered the story in detail. He also spoke of his concerns on yesterday’s Newsnight, which is definitely worth a look.

Continue reading "Cautious response to UK climate projections " »

Posted by Olive Heffernan on June 19, 2009
Categories: Climate prediction, In the News, Olive Heffernan, Regional climate | Permalink | Comments (2) | TrackBacks (0)

Cement and pinot noir were among the highlights of the AGU Joint Assembly in Toronto Tuesday.

Sequestration of carbon dioxide, that is, pulling it out of the air and storing it where it cannot affect climate as a greenhouse gas, is a quest that engages many scientists and engineers. Proposals have been made to store CO2 deep in the ocean and in depleted mines far underground. Soon, though, you may be able to walk on sequestered CO2, says Sidney Omelon, a chemical and materials engineer with Calera Corporation, a California start-up.

The purpose of a project under study and described in Omelon’s Joint Assembly poster Tuesday is to capture CO2 from concentrated sources, such as emissions from power plants. Step one is to channel the gas into an aqueous environment, in order to precipitate carbonate minerals. The novel part is what happens next. Calera is developing a process to incorporate this precipitate into the built environment, specifically in concrete used for street paving and buildings.

Cement, a key ingredient of concrete, is an ideal substance into which the precipitate can be added, Omelon said in an interview. She does not know of any other comparable projects. Surprisingly, in her view, it hasn’t been tried until now. “Honestly, I can’t believe no one [else] thought of it first,” she said.

Calera is also looking into using captured CO2 in aggregate, another key component of concrete. Even when concrete structures eventually crumble, the material itself would remain stable, Omelon said, and the CO2 would not escape to the atmosphere.

We are looking at CO2 as a resource, not just as a pollutant, Omelon concluded. “I think if we just turn our brains to this, we can do some really useful things with carbonate minerals and also just try and reduce our general energy consumption, so that we don’t emit as much CO2.”

Continue reading "AGU 2009 Joint Assembly: From paving to pinot noir " »

Posted by Olive Heffernan on May 26, 2009
Categories: AGU 2009 Joint Assembly, Harvey Leifert, Mitigation, Regional climate, Technology | Permalink | Comments (2) | TrackBacks (0)

Level 7 of the Metro Toronto Convention Centre is situated above Level 8, and Level 6 is higher still. Once you find your way around, it’s seems the perfect place to study atmospheric inversions and other climatological phenomena. That’s what is happening at the centre this week during the Joint Assembly of the American and Canadian Geophysical Unions, along with a half-dozen other Earth and space science societies.

This annual event, once known as AGU Spring Meeting, has attracted some 2,500 presentations, ranging from Atmospheric Science to Volcanology, and the ones touching on climate change turn up under a variety of headings. Climate change may occur globally, but it impacts locally, and regional impacts were the topic of numerous presentations Monday at Joint Assembly.

The issue facing researchers and policy makers alike is scaling down the results of global climate models to make useful predictions for specific locales, like cities, counties, or watersheds, predicting how climate change may affect local populations, industries, and wildlife.

In the US state of New Hampshire, for example, the multimillion dollar ski industry depends upon a large and consistent snowpack. Cameron Wake of the University of New Hampshire said that to be economically viable, ski operators must count on a season of at least 100 days, ideally including Christmas week. But, a group of regional scientists estimates that by 2100, New Hampshire will warm between 1.9o and 6.9o Celsius, the extremes of several models tested. The greatest warming will be in winter. Also, there will be more rain and less snow in winter, and anticipated droughts will further reduce the number of days with snow on the ground. By the 100-day standard, Wake said, and even with snowmaking equipment, almost all New England ski areas will be vulnerable by 2100.

New York City has always prided itself on its water supply. New Yorkers turn the tap and enjoy mountain spring water piped from protected watersheds far upstate. But will climate change affect the quality of that water—currently four million liters for nine million customers daily—in years to come? The city is actively addressing that question, said Mark Zion of New York’s Environmental Protection Agency.

Continue reading "AGU 2009 Joint Assembly: Global change, local impacts" »

Posted by Olive Heffernan on May 25, 2009
Categories: AGU 2009 Joint Assembly, Climate prediction, Harvey Leifert, Regional climate | Permalink | Comments (0) | TrackBacks (0)

Arctic sea ice continues to shrink, according to the latest satellite data. And in a scenario all too familiar to people of a certain age, the ice that is left has been replaced by a younger, thinner version of itself.

According to the US National Snow and Ice Data Center, the maximum extent of Arctic sea ice last winter was the fifth lowest on record. All sixth lowest maximums have occurred in the last six years (press release).

This year’s maximum was 15.16 million square kilometres, which is smaller than the 1979-2000 average by an area roughly the size of Texas (or France). Younger, thinner ice which melts every year is now 70% of Arctic sea ice, says the NSIDC, meaning melting is easier. In the 1980s and 90s this type of ice was between 40 and 50% of the total.

Read the rest of this post at Nature's The Great Beyond blog.

Posted by Olive Heffernan on April 07, 2009
Categories: Climate Science, Cryosphere, Daniel Cressey, Regional climate | Permalink | Comments (0) | TrackBacks (0)

When it comes to describing how human activities are altering the Earth’s climate, aerosol emissions can tie your tongue in knots. Airborne pollution particles grouped under the "aerosol" heading come in a wide assortment - and some, as this NRCC article explains, tend to absorb sunlight and heat up the atmosphere, while others are more reflective and cooling. On top of that, it’s been thought to make a difference whether this potpourri of pollutants ends up drifting in clear skies or above clouds. Coming in now are the first experimental data that show just how important the effect of cloudiness is.

A study out this week in Nature Geoscience (subscription) uses a new type of satellite data to look at the smoky haze wafting above the southeast Atlantic, mostly from fires in southern Africa, during July-October of 2006 and 2007. The findings confirm what models had suggested: aerosols over cloudier patches of ocean have a net warming effect, but they switch to cooling over unclouded ocean.

Simply put, a veil of aerosols darkens white clouds, but it lightens the dark surface of the sea, and this difference in reflectivity swaps the outcome. The authors, led by Duli Chand of the University of Washington, estimate that 40% cloud cover is the turning point where the southeastern Atlantic’s aerosol cocktail starts adding to greenhouse warming rather than subtracting from it. Cloud cover in the study averaged 48%, and the spatial distribution of clouds and aerosols also overlapped significantly. The overall warming that this produces is about three times what it would be if clouds and aerosols were floating around independently instead of near each other, the group finds.

Continue reading "Untangling aerosol effects" »

Posted by Anna Barnett on February 23, 2009
Categories: Anna Barnett, Atmospheric Science, Regional climate | Permalink | Comments (0) | TrackBacks (0)

Winners were announced Friday Thursday in a contest organized by the World Bank for short-short films - two to five minutes long - documenting the social dimensions of climate change. The 'Vulnerability Exposed' contest put out an open call last autumn for films to be posted on YouTube, with a special plea for documentation of developing-world impacts.

And the winner for vulnerability exposure is... Bangladesh! The judges' top pick and the runner-up focus on unpredictable floods in the country and its salinization by the rising sea - some of the same issues Mason Inman wrote about in NRCC recently.

The first-prize film, "Flood Children of Holdibari" by Mary Matheson, looks at children working out an adaptation plan for floods on their river-island home.

Second prize went to Rosa Rogers for "Climate Change in Bangladesh: Who Will Pay?", a film on how salinization and other effects are changing agricultural patterns in the southern delta.

Anna Barnett

Posted by Anna Barnett on January 26, 2009
Categories: Anna Barnett, Communicating Climate Change, Regional climate, Society | Permalink | Comments (0) | TrackBacks (0)

The UK will get an intriguing new climate research centre next week, with the launch of the Centre for Climate Change Economics and Policy at the London School of Economics and the University of Leeds. In a Q&A for Nature Reports Climate Change, I've interviewed Andrew Gouldson, who will co-direct the centre with Judith Rees under chairman Lord Nicholas Stern - and who envisions a strong focus on regional impacts of climate change.

CCCEP's experts will be closely in touch with policymakers and other local stakeholders, Gouldson says, in a way that "builds both their capacity and ours — ours to do good research, and theirs to use that research to take better decisions on climate change." One of the stakeholders, and a funder of one of the five research streams at the new centre, is the insurance company Munich Re. As I wrote last month, another new project that aims for the cutting edge of policy-relevant research is a hurricane model projection that Greg Holland is now wrapping up at NCAR - also partly insurance industry-funded. Could these academic-public-private three-ways be the way forward? Let us know in the comments.

I thought the most interesting part of the interview was what Gouldson had to say on the new UK Climate Change Act, which imposes a legally binding requirement to cut emissions 80% from 1990 levels by 2050. Here's an extract:

AG: At the national level, I think Britain's been very proactive indeed. The government has been quite brave signing up to this medium- to long-term target which is really quite ambitious. But I don't think there's a public understanding, or possibly even a public acceptance, of what a low-carbon economy might look like — one which is 60, 70, 80 per cent decarbonized.

AB: Does that make it less likely that the policy will actually come through with results?

AG: In the next 10 to 15 years, not necessarily, because there are lots of mitigation options that are relatively affordable and technologically viable. I think the question is what happens in the phase after that. Is there a political appetite to do some really quite painful things which would involve some powerful people or parties losing out? I think there's a need now, in the next few years, to build some sort of broad consensus on the need to shift towards a low-carbon economy.

Read the full interview here.

Anna Barnett

Image: Andrew Gouldson, photographed by Stevie Kilgour at the University of Leeds.

Posted by Anna Barnett on January 23, 2009
Categories: Adaptation, Anna Barnett, Climate Policy, Economics, Politics, Regional climate, Research, Society | Permalink | Comments (1) | TrackBacks (0)

A study published in Science today (subscription) uses carbon-14 measurements to figure out where the black carbon drifting in the haze above South Asia is coming from. That’s a prerequisite to cleaning it up - which, as we’ve reported here, could be a major boon to a very vulnerable region. The light-absorbing compound not only causes cancer (among other ill health effects), but reportedly warms some places as much as greenhouse gases do. Because its lifespan in the atmosphere is far shorter than carbon dioxide’s, these impacts could potentially be reduced quickly - if we knew where to clamp down.

Writing in Science, Örjan Gustaffson of Stockholm University and colleagues call black carbon the "dark horse" in the current climate debate, saying “substantial uncertainties exist about its atmospheric longevity, aerosol mixing state, measurement, and sources.” Black carbon is unusually concentrated in the ‘brown cloud’ over South Asia, they note. But estimates vary wildly on how much of this is from fossil fuel burning and how much from smoky fires of wood, dung and other biomass: the ratio ranges from about 1:10 to 10:1, depending on the technique and study area.

Radiocarbon measurements give a more reliable read on this question than other methods, according to Sönke Szidat of the University of Bern, who discusses the new paper in an accompanying Perspective. The principle is simple: fossil fuels are ancient enough that all their carbon-14 has decayed away, whereas freshly gathered biofuels have plenty of the isotope. And while other chemical clues about the brown cloud can change as it wafts around, carbon-14 stays stable.

The carbon-14 levels tell Gustaffson et al. that around half of the black carbon in the cloud, or more, is from biomass. They took samples at ground stations in the Maldives and atop a West Indian mountain, downwind of the rest of South Asia. The 50% figure, Gustaffson says, comes from a method of isolating black carbon that picks up airborne coal dust as well as combusted carbon in soot; in soot-only samples, about two-thirds was from biomass.

Says Szidat:

The study shows that the importance of biomass burning for local and global BC [black carbon] budgets has been underestimated. This was previously pointed out for urban, rural, and remote areas in Europe, but never were the consequences as severe as for the Asian haze.

Continue reading "Biomass, biomass, burning black" »

Posted by Anna Barnett on January 22, 2009
Categories: Anna Barnett, Atmospheric Science, Regional climate | Permalink | Comments (0) | TrackBacks (0)

As a vast, flat delta, Bangladesh is perhaps the country most clearly associated with the threat of rising seas – without protective barriers along the coast, even a moderate increase in sea level could cause flooding deep inland. Estimates suggest that even a one-metre rise could swallow 15 to 20 per cent of the land area, where some 20 million people reside.

But while sea level rise may pose the greatest challenge for Bangladesh, the accumulation of greenhouse gases in the atmosphere is likely to be felt at ‘ground zero for climate change’ in numerous different ways – among them dwindling water supplies, saltwater damage to crops, loss of biodiversity and fiercer storms tearing through the region.

Over on Nature Reports Climate Change, a feature by Mason Inman looks at the changes that are already being witnessed on the ground in Bangladesh and how the region is preparing for the changes yet to come. Mason travelled to Bangladesh in November to report this feature with support from a Middlebury Fellowship in Environmental Journalism.

In areas such as Bhola, where people have lost land to the ocean, many are looking to the Netherlands for inspiration – and calling for strengthening of existing embankments as well the construction of new, taller and stronger sea walls.

Continue reading "Bangladesh’s battle with climate change " »

Posted by Olive Heffernan on January 15, 2009
Categories: Adaptation, Olive Heffernan, Regional climate, Society | Permalink | Comments (0) | TrackBacks (0)

Over the past 24 hours, some 15,000 earth scientists descended on San Francisco for the annual Fall conference of the American Geophysical Union. Delegates were a dead give away at the airport and on the BART yesterday with their large poster tubes in tow. It’s my first AGU and it could be the jet lag, but I’m feeling slightly overwhelmed by the sheer size and number of parallel sessions; at any given time I could be at one of at least four climate-related talks and invariably find myself wondering why the session next door is receiving louder applause.

A number of talks today focused on the need for climate science to become less curiosity driven and more specific to the needs of stakeholders such as local authorities and natural resource managers.

This is a topic that’s been getting a lot of attention recently. Earlier this year, for example, scientists called for a billion dollar investment in climate computing facilities to enable regional scale climate predictions on decadal time scales. At a press conference this morning, scientists including Jonathan Overpeck from the University of Arizona and Jack Fellows of UCAR highlighted the importance of partnerships between universities and decision makers in enabling states and regions to plan for climate change.

Continue reading "AGU 2008: conference kicks off " »

Posted by Olive Heffernan on December 16, 2008
Categories: AGU, Climate prediction, Features, Olive Heffernan, Regional climate, Research | Permalink | Comments (3) | TrackBacks (0)

The Great Plains of the United States, late twenty-first century: breadbasket or dust bowl?

It may depend on groundwater storage, finds a study published in Nature Geoscience this week (subscription required). The results are based on an unusually sophisticated watershed model that connects the below-ground water sources, surface water and the land surface itself.

Continue reading "Breadbasket or dust bowl?" »

Posted by Anna Barnett on September 30, 2008
Categories: Anna Barnett, Climate Science, Earth science, Regional climate | Permalink | Comments (3) | TrackBacks (0)

Global warming has been expected to bring not only droughts, but also floods, because what rain you get comes hammering down harder. And the downpours of the future now look to be even more drenching than expected.

A new Nature Geoscience paper (subscription required) considers the intensity of precipitation measured hour by hour for a century in the Dutch town of De Bilt. Theoretically, it’s thought that the intensity of rainfall, including the biggest cloudbursts, should rise by 7% for each degree Celsius that the temperature goes up. That’s based on a thermodynamics equation called the Clausius-Clapeyron relation - and it’s what you see if you look at extreme rainfall on the scale of days.

But it's the rainiest hours, not the rainiest days, that interest the paper's authors, Geert Lenderink and Erik Van Meijgaard of the Royal Netherlands Meteorological Institute. That turns out to make a difference.

Continue reading "A precipitous rise in extreme rainfall " »

Posted by Anna Barnett on July 21, 2008
Categories: Anna Barnett, Climate variability, Extreme Events, Regional climate | Permalink | Comments (1) | TrackBacks (0)