Geoengineering


A working group commissioned by The Pontifical Academy of Sciences [website & wikipedia entry] “to contemplate the observed retreat of the mountain glaciers, its causes and consequences” has released a report entitled Fate of Mountain Glaciers in the Anthropocene.  The groups consensus statement is a warming to all humanity and a call for fast action.  This is their declaration:

“We call on all people and nations to recognise the serious and potentially irreversible impacts of global warming caused by the anthropogenic emissions of greenhouse gases and other pollutants, and by changes in forests, wetlands, grasslands, and other land uses. We appeal to all nations to develop and implement, without delay, effective and fair policies to reduce the causes and impacts of climate change on communities and ecosystems, including mountain glaciers and their watersheds, aware that we all live in the same home. By acting now, in the spirit of common but differentiated responsibility, we accept our duty to one another and to the stewardship of a planet blessed with the gift of life.

We are committed to ensuring that all inhabitants of this planet receive their daily bread, fresh air to breathe and clean water to drink as we are aware that, if we want justice and peace, we must protect the habitat that sustains us. The believers among us ask God to grant us this wish. “

A pdf of the complete statement can be accessed here.  The authors recommend pursuit of three measures:

  • immediate reduction of worldwide carbon dioxide emissions,
  • reduction of concentrations of warming air pollutants such as soot, ozone, methane and hydroflurocarbons by up to 50 percent, and
  • preparation to adapt to climate changes that society will not be able to mitigate.

An interesting story I read on the BBC website yesterday entitled ‘Can painting a mountain restore a glacier?’.  A local community in Peru are painting a mountain white using lime, industrial egg white and water.  The aim being to change the surface albedo (a measure of how strongly an object reflects light).  Whitewashing the mountain will mean the sunlight is reflected off the surface (rather than being absorbed) and thus cooling the microclimate hopefully making conditions more favourable for the disappearing glacier.  Will this be enough to save the glacier – who knows!  A couple of degrees lower could be enough to slow or holt the decline, at least in the short-term. Of course it will not change the regional decline of glacier coverage in the Andes.

Geoengineering is the scientific term used to describe deliberately manipulating physical, chemical, or biological aspects of the Earth system.  If mitigation (reducing emissions) and adaptation (increasing capacity to cope with climate impacts) fail then large scale geoengineering may be required as a last resort to reduce major negative consequences of climate change.  A position statement on geoengineering the climate system from the American Geophysical Union (AGU) of which I belong can be found here.  Elsewhere the Royal Society of London has published a comprehensive report (details found on this page) that also advocates extreme caution in the possible use of such approaches and their feasibility while encouraging research efforts in this interesting area.