Climate Change

Snail shells provide detailed records of environmental change

By Dr Jonathan Lewis and Prof Melanie Leng The shells of molluscs from all over the world – on land, in lakes, and in the ocean – contain very detailed imprints of past climate change. Using isotope analysis, we can extract these signals and start to piece together long-term climate variations. You will never look at a garden snail in the same way again! What are molluscs? Molluscs are soft-bodied (invertebrate) organisms that are widespread in terrestrial, freshwater, and marine habitats. We can split them into two basic groups: Gastropods: Molluscs with up to one shell or ‘valve’ (such as snails or slugs) Bivalves: Molluscs...

In brief: the UN Climate Summit

This week, delegates from the UN met in New York to discuss global climate change and to develop strategies for tackling these issues.  What are the outcomes of their discussions? And what does this mean going forwards? #climate2014   The meeting in New York was the largest climate meeting since Copenhagen 2009, and 120 world leaders took part in discussions. As well as discussing issues surrounding climate change, the summit aimed to encourage member states of the UN to sign the global climate agreement, which will be announced next year in Paris.  The talks focused on eight areas: agriculture, cities, energy, financing, forests, industry, resilience,...

Volcanoes and climate change

What happens to the atmosphere when volcanoes erupt? Can volcanic eruptions lead to climate change? In 2010 the eruption of Eyjafjallajökull in south Iceland brought air traffic in northern Europe to a standstill for almost seven days. Now, the Bárðarbunga volcano, which has erupted beneath the Dyngjujökull glacier in central Iceland, is being intensively studied by scientists. On average, there are around 50-60 volcanic eruptions around the world each year. When volcanoes erupt, they can emit huge volumes of gases, aerosols, and volcanic ash into the stratosphere (part of the atmosphere at around 10-45 km altitude http://climatica.org.uk/climate-science-information/earth-system). With all of this material, we might expect...

Can isotopes help define the Anthropocene?

By Dr Jonathan Dean, Prof Melanie Leng and Prof Anson Mackay   The Anthropocene is a term that is increasingly being used to refer to the current interval in geological time in which humans have become a dominant force of global environmental change. It was coined by Prof Eugene Stoermer, a biologist, in the 1980s and popularised in the early 2000s by Prof Paul Crutzen, an atmospheric chemist. It is now indisputable that humans are leaving their mark on the planet (see the recent Climatica summary of the ‘Climate change: evidence and causes’ report here: http://climatica.org.uk/royal-society-national-academy-sciences-climate-change-evidence-causes). For instance, over the last century or so, atmospheric...

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...