Wednesday, 28 March 2012

Alex Stubbings: What's Driving Climatic Change Today?

Alex Stubbings is our GfGD Blog Climate Change Correspondent, and will be blogging on all matters related to climate change, climate change adaptation, and the important role geoscience can play in this discipline. Alex has a BSc in Environmental Geology from the University of Birmingham and an MSc in Climate Change from the University of East Anglia, as well as experience working in Bangladesh. In the first of special series, a fortnight ago he wrote about the Earth's Changing Climate. Today he looks at what is driving climatic change today...


Keeling Curve (Source: Wiki)
Climate Change (2) - What's driving climatic change today?

How do we know that climatic change is occurring today? Well this is extremely nuanced and requires multiple lines of enquiry to provide robust and reliable data/ information. Firstly, there’s the longest climatological record in the world: the Central England Temperature record, dating back to the 17th Century – despite heterogeneities in the data. Secondly there’s the work of chemists and atmospheric chemists from the late 19th and early 20th Century’s – this book provides an authoritative historical narrative, (and also see here) - who provided the necessary empiricism to prove that the natural greenhouse effect exists, artificially increasing Earth’s ambient temperature within the habitable zone. Thirdly, and most crucially, the work of David Keeling: the Keeling Curve. This curve alone provides significant and robust evidence that pCO2 levels have been increasing since monitoring began in the early 1950s.

However, the backdrop to current climatic change is, overwhelmingly, due to global economic development since the Industrial Revolution, and to a lesser extent, but still as important, the Agricultural Revolution – (also see here).

Source: Wiki
The exploration and exploitation of hydrocarbon reserves is predominantly responsible for increased climatic variability that we have been observing since the latter half of the 20th Century. However, whilst through their combustion hydrocarbons provide the increased majority of greenhouse gases to the atmosphere, land-use, land-use change and forestry (LULUCF) also contribute to the problem.

Whilst CO2 is labelled the main agent of contemporary climatic change water vapour, methane (CH4, see here and here) and CFCs all have a role to play. Water vapour is more significant than CO2 in a warming world, and has a much stronger global warming potential. This article from GSA Today does a very good job of explaining how the increased concretion of natural, and un-natural, greenhouse gases in the atmosphere results in climatic change observed around the world today.

In many regions of the world today, even in OECD nations, climatic change is already having adverse effects on peoples livelihoods for example: melting glaciers, sea level rise, erratic rainfall, unusual temperatures and an increase in storms are severely affecting communities. Climatic change will negatively impact the world’s poorest as they have the least resilience and coping capacity to deal with sudden disasters or creeping hazards. Quite often their livelihoods are severely affected and they’re pushed back into poverty. The challenge for geoscientists in an ever changing, and fast changing world, is to utilise their knowledge of past climatic events, such as the Palaeocene-Eocene Thermal Maximum –despite the factors forcing climatic change being very different. This knowledge can be used to work with policy makers and development practitioners to deliver real, scaleable and affordable solutions to communities most vulnerable and exposed to the detrimental effects of climate change.

(Alex will be writing about the impact of climate change on developing countries in his next post on Monday 9th April)