Climate Change

What is climate change? 

Climate change refers to long-term changes in temperatures (i.e. global warming) and weather patterns. The earth’s climate has changed throughout history, so the phenomenon is not new. What is new is the speed and magnitude of change recorded over recent decades. 

According to the United Nations (UN), the average temperature of the earth’s surface is now ~1.1°C higher than it was before the industrial revolution and the highest in the last 100,000 years. The decade between 2011 and 2020 was the warmest on record, and each of the last four decades has been warmer than any previous decade since 1850. Moreover, July 2023 was by far the hottest July on record and likely the hottest it has been in 120,000 years. 

According to the UN, there is overwhelming scientific evidence that climate change over the last two centuries is man made. 

How does it manifest itself? 

Beyond an increasing average temperature of the earth’s surface, climate change manifests itself in many other ways. For example, over the last four decades the global mean sea surface temperature has increased by ~0.6°C – according to NASA, around 9/10th of global warming is occurring in the oceans. Increasing ocean temperatures have been linked to increasing hurricane intensity, while rising temperature levels generally have accelerated the melting of polar ice caps, resulting in rising sea levels (these have risen by more than 20 cm since 1880), and of glaciers in the mountain ranges of the world.

Changing weather patterns are also reflected in changing global patterns of precipitation, for example in less frequent but more intense rainfall, and wind patterns, both in terms of direction and speed. The impact of climate change will vary across regions or even local areas. 

According to the Met Office climate change can also explain the rise in more intense and frequent warm spells and fall in more intense and frequent cold spells in the UK. Central England temperatures have risen markedly since records began in the 1880s. The linkage to heavy rains, dry spells and storms remains inconclusive though. 

What are the consequences globally? 

Consequences include: 

• rising land temperatures which affect biodiversity and wildlife and raise risk of wildfires (e.g. Australia 2019/20, USA 2020, Canada 2023), potentially hitting human settlements 
• rising sea levels which raise the risk of coastal flooding, potentially hitting human settlements 
• lack of new snow fall and melting glaciers which raise risk of water shortages, for example in the Americas (e.g. Maipo river basin in the Andes, Colorado river basin in the Rocky Mountains) and in South Asia (e.g. Indus river basin in the Himalaya) 
• extended and less predictable dry spells which raise risk of droughts, crop failures and food insecurity, potentially making regions uninhabitable and triggering international migration 
• more intense rain falls which raise risk of river flooding, potentially hitting human settlements 
• rising sea temperatures which affect biodiversity and sealife. More frequent and strong hurricanes, cyclones and typhoons could hit human settlements 
• excess mortality as a result of more frequent and extreme heatwaves. 

What are the consequences in the UK? 

According to the UK Government Actuary’s Department, the net effect of temperature change on excess mortality – that is the number of deaths above what would be expected under ‘normal’ conditions – so far has been negative, with lower excess deaths as a result of milder winters more than offsetting higher excess deaths as a result of hotter summers. 

Why does it matter? 

If you would like to find out more about the topics discussed in this factsheet and how we might be able to help you with ESG reporting, please talk to us.