Climate Change

Desertification: land degradation under a changing climate

Today, 17th June, is the World Day to Combat Desertification, with an event being held by the United Nations Convention to Combat Desertification (UNCCD), and hosted at the World Bank in partnership with the Global Environment Facility (GEF), TerrAfrica and Connect4Climate. The UNCCD have recently published a comprehensive report on the impacts of desertification. Here we look at what desertification is, how it is affected by climate change, and what this means for global populations. What is desertification? Desertification is a form of land degradation by which land becomes more arid.  It’s definition is debated, but it generally refers to “the process of fertile land transforming into desert typically as a result...

Quaternary science in the UK: 50 years of past climate research

2014 is a big year for Quaternary science! In January, the UK Quaternary Research Association (QRA) celebrated its 50th anniversary at the Royal Geographical Society in London. The QRA is a research organisation which focuses on the Quaternary Period – the last 2.6 million years of Earth’s history, which is broadly synonymous with ‘The Ice Age’. Quaternary science (the study of all things Quaternary) encompasses a wide range of research fields including: oceanography, glaciology, ecology, and human evolution. These strands of Quaternary research come together to build a detailed picture of the long-term changes in the Earth’s environment. Every year the QRA hosts an Annual...

The Royal Society and National Academy of Sciences – Climate Change: Evidence & Causes

“Climate change is one of the defining issues of our time. It is now more certain than ever, based on many lines of evidence, that humans are changing Earth’s climate. The atmosphere and oceans have warmed, accompanied by sea-level rise, a strong decline in Arctic sea ice, and other climate-related changes.” Dr. Ralph J. Cicerone (President, National Academy of Sciences) and Sir Paul Nurse (President, Royal Society)   On Thursday last week, the Royal Society and the US National Academy of Sciences, two of the most prestigious science academies in the world released an overview of “Climate Change: Evidence and Causes”. This publication aims to provide authoritative...

IPCC special: Long-term climate projections

Chapter 12 of the 5th Assessment Report of IPCC (Intergovernmental Panel on Climate Change) deals with future projections of climate change in the long-term. Long-term in this case means beyond the middle of the 21st century when the projections start to depend more strongly on the pathway or scenario of emissions of greenhouse gases, principally CO2. We rely extensively on computer models of the climate system for this as, obviously, there are no observations of the future. While computer models are not completely accurate in their ability to project future climate change, it is possible to use our understanding of the climate system to assess uncertainties...

Measuring Greenhouse Gases

It is not at all trivial to make precise measurements of greenhouse gas concentrations in the atmosphere, but exactly this is needed when assessing climate change impacts from human emissions. Only when present concentrations are known as accurately as possible can long-term trends be identified and seasonal variability be studied. The three most important greenhouse gases in the atmosphere are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Several clean air measuring stations around the world, with Mauna Loa the most well known, form a global network to monitor atmospheric concentrations. One of these stations is Baring Head, close to Wellington in New Zealand....