(BY HUGO)

Thanks to collegue BO, who pointed to this article from Karl Burkart from the Mother Nature Network, about manufacturing clouds to increase the albedo of the Earth's athmosphere and presumably reduce greenhouse effect by reflecting the Sun's energy back into space:

«Basically a fleet of ships equipped with screens & vacuums pump up millions of gallons of ocean water and using high-powered water canons introduce the water some 3000 feet in the air, where clouds are formed. The added moisture content would increase the thickness of the water vapor, making the clouds whiter and thus more reflective.»

The proposals for such experiments have been around for years and are part of a wider debate about geoengineering to fend off the anticipated damages resulting from global temperature increases. As reported by Ben Webster for the Times:

«The British and American scientists involved do not intend to wait for international rules on technology that deliberately alters the climate. They believe that the weak outcome of December’s climate summit in Copenhagen means that emissions will continue to rise unchecked and that the world urgently needs an alternative strategy to protect itself from global warming.»

Of course, the resulting alteration of precipitation patterns is completely unpredictable, adding to the increasing variability of water flows in the hydrologic cycle due to climate change.

Why invest massively into such magic-wand solutions rather than into concrete projects to counter green gas emissions? No clue. It just makes no sense, however you want to look at it. The point is, nobody knows the effect of such extreme measure; it's conjectures piled on conjectures,buttressed by conjectures.

Fortunatly, common sense has not entirely left the building. In the current discussions of the scientific advisory body to the Convention on Biodiversity, SWEDEN and ARGENTINA called for applying the precautionary principle to geoengineering. IISD provides some highlights to follow the action here.

It feels like humanity realised it will inevitably crash against a wall, but instead of breaking just decided to accelerate to reduce the damages. Depressingly, great environmentalists like the people at Legal Planet start considering geoengineering solutions as a reasonable possibility.

(BY HUGO)

302 companies have been asked to report their water usage by the investor-backed Carbon Disclosure Project (CDP), which issued its first water-disclosure questionnaire this week.

As reported in this article from Vincent Bevins, Marcus Norton, head of CDP Water Disclosure, said that «the project is the result of investors who are concerned about three risks: physical scarcity, increased regulatory action – which can deny access or raise prices – and damage to a company's public image.»

Justification for disclosure of the water-related risks is articulated in this CDP Report as follows:

«business disclosure of water-related risk will also have a number of valuable benefits:

1. Raising businesses awareness and requiring enhanced understanding of their own issues, risks and opportunities;

2. Supporting efforts to develop standard measures and performance benchmarks;

3. Providing investors, regulators and other stakeholders with better information;

4. Raising general awareness of water-related issues; and

5. Encouraging action and dialogue.» (p.9)

Findings from the project are planned to be released between Octobre and December 2010.

(BY HUGO)

The Tyndall Centre for Climate Change Research published the Four Degrees and Beyond Special Issue of the Philosophical Transactions of the Royal Society A Journal (link), with an interesting article by Fai Fung, Ana Lopez & Mark New on «Water availability in +2°C and +4°C worlds».

The paper contrasts water availability and water stress in a world where warming is limited to 2◦C as per the Copenhagen undertakings and one where policy fails and warming reaches 4◦C, a likely scenario according to scientific sources quoted.

The paper defines a water stress index (WSI) based on water resources per capita calculated as the ratio of mean annual surface run-off (MAR) to population. This is recognized as simplistic and reference is made to more complex models in the literature on water stress or scarcity, but a simpler index is justified to reduce uncertainty and limit data requirements. Some interesting parts of the paper discussion are as follows:

«changes in mean annual run-off in a +2◦C world are generally amplified in a +4◦C world: drier areas dry further and wetter areas become wetter. Moreover, as these changes in MAR become amplified, both the consensus and spatial coherence of these changes strengthen. By investigating the changes in water stress in 112 of the world’s major river basins, we have also found that the majority of these river basins are projected to suffer greater water stress in a +4◦C world than in a +2◦C world. However, as we move from a +2◦C to a +4◦C world, there are also a small but increasing number of basins that may experience less water stress, as they are located in regions where rainfall is projected to increase. By using population growth scenarios for the 2030s and 2060s, we find that in a +2◦C world, water stress is dominated by the change in population. However, as we move to +4◦C world and the climate change signal becomes stronger, climate change can play a more dominant role in determining water stress in a river basin. (...)

By examining a subset of the world’s major river basins, we have shown that the picture for water stress in each river basin is dependent on the magnitude of the climate change and the nature of the population growth. For some river basins, the effects of climate change become large enough to offset the large increases in demand in a +4◦C world, e.g. in the Ganges; in most basins, however, climate and population growth combine to increase stress or climate change is insufficient to offset increased demand.

We have also found that seasonality in run-off may be more pronounced in a +4◦C world compared with a +2◦C world; thus, even where annual average runoff increases, dry seasons can become more stressed. This could mean that more sophisticated infrastructure projects may be required in a +4◦C world compared with a +2◦C world in order to prevent flooding and droughts.»

Given the business as usual approach to adaptation in Québec, this could mean that trends in dam building and supply oriented solutions will continue to amplify. Possible impacts of dams on the environment at the provincial level might depend on changes to reservoir release regimes under which the dams must operate (inversion, homogenisation, natural) in order to adapt to climate change. As most large dams operate for power generation, modifications in energy demand to face climate change could be an important factor influencing flow regimes and alterations patterns to freshwater ecosystems. Reductions in heating during winter, increase in climatisation duing summer and increased seasonal run-off variability might all point to a move away from natural reservoir release patterns and towards homogenisation or inversion regimes. The Ouranos Consortium has published studies regarding some aspects of climate change on Québec water resources.

(BY HUGO)

A recent article from Aiguo Dai, «Drought under Global Warming: A Review», published in Wiley Interdisciplinary Reviews: Climate Change on 19 October 2010, reviews recent literature on drought of the last millennium, and provides an update on global aridity changes from 1950 to 2008. Projected future aridity is also presented based on recent studies and our analysis of model simulations.

The article provides a typology of droughts: meteorological drought; agricultural drought; and hydrological drought, which might be the more difficult to address because it occurs when river stream flow and water storages in aquifers, lakes, or reservoirs fall below long-term mean levels, thus probably requiring systemic adaptation in water allocation patterns and total consumption.

Interesting points from the article are as follows:

- «Successive "megadroughts", unprecedented in persistence (20–40 year) yet similar in severity and spatial distribution to the major droughts experienced in modern day’s North America, occurred during a 400-year-long period in the early to middle part of the second millennium AD over western North America. Compared with these multi-decadal droughts, the modern-day droughts in the 1930s and 1950s had similar intensity but shorter durations.» (p.4, references omitted)

- «One should not use total precipitation alone to measure changes in aridity or drought, as done in many studies. Increased heavy precipitation and reduced light to moderate rain can increase the runoff to precipitation ratio, and increases in surface air temperature and radiative heating can lead to higher atmospheric demand for moisture. These processes can result in drier soils even if the precipitation amount increases.» (p.13, references omitted)

- «Although natural variations (...) have played a large role in the recent drying, the rapid warming since the late 1970s has increased atmospheric demand for moisture and likely altered atmospheric circulation patterns (e.g., over Africa and East Asia), both contributing to the recent drying over land. Since a large part of the recent warming is attributed to human-induced GHG increases, it can be concluded that human activities have contributed significantly to the recent drying trend.» (p.15, reference omitted)

- «Coupled climate models used in the IPCC AR4 project increased aridity in the 21st century, with a striking pattern that suggests continued drying over most of Africa, southern Europe and the Middle East, most of Americas (except Alaska, northern Canada, Uruguay, and northeastern Argentina), Australia, and Southeast Asia.» (p.15)