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The A to Z of Climate Change


Climate change can be a complicated and confusing topic.  For many people it seems abstract and irrelevant to their lives, but with so many species, habitats and people being impacted it’s becoming ever more important to engage with.

To celebrate the fiftieth anniversary of International Literacy Day, I’m sharing my A-Z of climate change, covering many of the terms you’re likely to see in the media today.  I was onto a pretty good start with Adaptation, Biodiversity, Climate Change and Deforestation.  Sometimes I had to choose between two or more good options, for example should R be Renewables, or Range shifts, or Rainforest?  Towards the end it got tougher – my Q is obscure and X more or less beat me but my Z let me talk about coral bleaching.  I hope you find this A-Z of climate change inspiring and informative.

A – Adaptation

The adjustment in natural or human systems to actual or expected climate and its impacts. Adaptation efforts include the use of drought-resistant crops, adoption of water conservation measures and building of storm surge barriers. Wildlife try to follow their preferred climate in behaviour called range shifting, which is also an adaptation.

B – Biodiversity

The variety of plant and animal life in a particular habitat. Climate change is forcing biodiversity to adapt – with many species shifting habitat and changing their life-cycles. Climate change can amplify existing threats and increase biodiversity loss.

Snow leopard In Winter © Klein & Hubert / WWFSnow leopard In Winter © Klein & Hubert / WWF

C – Climate change

The global or regional-scale change to long-term weather patterns and global warming is the long-term trend of rising average temperatures. The Earth’s climate has changed throughout history but since the industrial revolution warming, and related climate changes, are largely attributed to higher atmospheric concentration of carbon dioxide (CO2) caused mainly by burning fossil fuels.

London climate march 2014People gather in London for the Peoples Climate Change March, September 2014 © WWF-UK

D – Deforestation

A staggering 8.8 million hectares of natural forest is lost per year (more than four times the size of Wales). Deforestation and forest degradation leads to the release of carbon stored in the trees and are a big source of man-made greenhouse gas emissions and driver of climate change.

E – Energy

Clean and affordable energy is important for sustainable development. We need to transform the global energy-system to 100% renewable energy sources such as wind and solar from one reliant on burning fossil fuels such as coal, oil and gas, as energy from fossil fuels is the biggest contributor to climate change.

F – Food

Both food and the agriculture system are big drivers of climate change, with 14.5% of global greenhouse gas emissions coming from livestock. Changing patterns of consumption to eat less meat is one way of cutting emissions from our food system.

G – The greenhouse effect

The warming of the lower atmosphere due to certain gases allowing sunlight through, which then reflects off the Earth’s surface as infrared radiation, and becomes trapped. Without the natural greenhouse effect the Earth would be very cold, but the additional accumulation of man-made greenhouse gases is leading to adverse effects.

H – Heat waves

Heat waves are periods of abnormally hot weather and are associated with an increased number of deaths.  Heatwaves, drought and heavy rainfall are all examples extreme weather events.  Warming increases the likelihood of extremely hot days and for some extreme events, science can quantify probability or intensity changes due to climate change.

An almost dried up farmer's watering hole on a farm near ShepperAn almost dried up farmer’s watering hole on a farm near Shepparton, Victoria, Australia. Watering holes have dried up and stocking rates on many farms have dropped as the land can no longer support as many beasts. © Global Warming Images / WWF

I – Impacts

Impacts of climate change are already occurring and at record rates – these include rising temperatures, shifting seasons, rising sea-levels, disappearing Arctic sea-ice and more intense heat waves. Globally climate change impacts hit the poorest and most vulnerable hardest. UK risks have been assessed in a report by the Committee on Climate Change.

J – Just transition

A just transition to a low-carbon and climate-resilient economy, refers to the concept of providing workers with decent jobs, while protecting the environment. During the transition there will be fewer jobs in high-carbon industries and more in green technology.

K – Keeling Curve

The Keeling Curve shows atmospheric CO2levels measured at Hawaii’s Mauna Loa Observatory. Human activities, such as burning fossil fuels, has led to a ~27% increase from 315 parts per million (ppm) in 1958 to over 400 ppm in 2016.

Keeling CurveThe famous Keeling Curve, showing the increase in atmospheric carbon dioxide levels since monitoring began © Scripps Oceanography

L – Loss and damage

This refers to the negative impacts of climate change that occur regardless of efforts to cut global greenhouse gas emissions and efforts to adapt. Loss and damage can result from extreme events such as tropical storms and slow-onset events such as sea-level rise. Developing countries are particularly vulnerable.

M – Mitigation

Efforts to cut the rate of man-made emissions of greenhouse gas into the atmosphere. Climate change mitigation includes actions such as switching from polluting fossil fuels to clean renewable energy sources, improving energy efficiency, lowering consumption, improving transport, and stopping deforestation.

N – Nitrous oxide

Also known as laughing gas, nitrous oxide (N2O) is the third greenhouse gas in terms of contribution to global warming after CO2 and methane (CH4). N2O occurs naturally and is also caused by human activities such as agriculture, burning of fossil fuels and industrial processes.

O – Oceans

Oceans play an important role in the climate system. The world’s oceans absorb around 30% of the CO2 we pump into the atmosphere which keeps atmospheric concentrations and hence warming lower, but as a consequence causes ocean acidification, which can dissolve shells of tiny marine species, damaging the food chain.

P – Paris Agreement

2015 saw the confirmation of a historic deal between 195 countries to address climate change. The Paris Agreement aims to keep global warming to well below 2°C above pre-industrial levels and to pursue efforts to 1.5°C. It highlights the importance of adaptation and national mitigation to cut greenhouse gas emissions after 2020.  It is likely to enter into force in 2016.


Also known as ‘Quantified Emission Limitation and Reduction Objectives’ are the targets which many developed countries committed to as part of the Kyoto Protocol under the UNFCCC.

R – Range shifts

Plants and animals survive and reproduce in areas with a suitable climate. As the planet warms those species fast enough typically try to track their favoured climate towards the poles and uphill; those unable to – due low dispersion rates or barriers such as mountains or cities – may face local extinction.

S – Sea-level rise

This has adverse impacts on people and wildlife in coastal and low-lying areas – including submergence, coastal erosion and saltwater intrusion. The global mean sea level increased 19cm between 1901 and 2010 and is rising by more than 3mm per year – mainly due to thermal expansion and melting of land ice.

T – Temperatures

There was a record global average of 1°C above pre-industrial levels in 2015, and 2016 is set to break that. The temperature rise varies in different regions of the globe, with the Arctic warming faster than average. To avoid the worst impacts of climate change global average surface temperature rise should be limited to 1.5°C.

Arctic sea ice map © NOAAArctic sea ice map © NOAA


UNFCCC stands for the 1994 United Nations Framework Convention on Climate Change. The ultimate objective of the UNFCCC is to prevent “dangerous” human interference with the climate system. The UNFCCC spawned two further treaties to pursue this objective – the Kyoto Protocol, which entered into force in 2005, and the Paris Agreement negotiated in 2015.

V – Vulnerability

The vulnerability of a species describes the degree to which it will survive under climate change. The Intergovernmental Panel on Climate Change (IPCC) define vulnerability as the propensity or predisposition to be adversely affected by climate change; it encompasses a variety of concepts including sensitivity or susceptibility to harm and lack of capacity to cope and adapt.

W – Water

An important medium through which climate change influences the Earth’s ecosystem – a warmer atmosphere can hold more moisture. Freshwater resources can be impacted by climate change with concerns including rainfall reliability (persistent droughts for some areas and repeated floods in others), groundwater levels and decline in water supplies stored in glaciers and snow cover.

X – X

The first unknown quantity.

Y – Yearly greenhouse gas emissions

Emissions are rising and are estimated at around 47.6 billion tonnes CO2 equivalent for the world in 2012. UK greenhouse gas emissions in 2014 were 514.4 million tonnes CO2 equivalent; this is 35% below 1990 levels.

Z – Zooxanthellae

These are algae living in the tissue of healthy coral.  When water is too warm, corals expel the zooxanthellae and turn white – this is called coral bleaching. In 2014 global warming, combined with El Niño caused the longest recorded global coral bleaching and die-off.

In my A-Z I’ve tried to cover some of the reasons we need to act on climate now and some issues that climate change encompasses.

There is momentum internationally with the world’s two biggest greenhouse gas emitters, China and the US, ratifying the Paris Agreement ahead of the G20 summit last weekend.  It is vital we ensure that politicians in the UK continue to see dealing with climate change a priority.  Two steps the UK could take to stand up and be counted are to quickly ratify the Paris Agreement and to clarify how they intend to meet their international promises to reduce the UK’s emissions in a low-carbon plan.

To find out more about climate change and WWF’s climate change and energy work take a look at our website.

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