The effects of climate change

The potential effects of climate change are serious and represent a significant threat to the Earth and its population.

The warming of our climate system is undeniable. The atmosphere and oceans have warmed, the amounts of snow and ice have diminished, sea levels have risen, and the concentrations of greenhouse gases have increased. Many of these changes we have observed are unprecedented.

Human influence on the climate system is clear: evidence suggests that it is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.

What effect will climate change have at international level?

In 2013, the Intergovernmental Panel on Climate Change produced Climate Change 2013: The Physical Science Basis of Climate Change, a report on the direct observations of recent climate change across the globe.

A further report, entitled Climate Change 2014: Impacts, Adaptation and Vulnerability stated that it is extremely likely that human influence has been the dominant cause of observed warming since the mid-20th century and that In recent decades, changes in climate have affected natural and human systems on all continents and across the oceans.

What effect will climate change have at UK level?

The UK Climate Projections (UKCP09) are the most up-to-date sources of climate information for the UK. Using a number of variables and scenarios, the projections identified hotter, drier summers and milder, wetter winters as key trends.

We can also expect to see:

  • an increase in summer heat waves, extreme temperatures and drought;
  • increased frequency and intensity of extreme precipitation events;
  • a reduced occurrence of frost and snowfall;
  • a rise in sea levels (depending on emissions scenario – central estimates of sea level rise in Edinburgh are 10-18 cm by 2050 and 23-39 cm by 2095).

What effect will climate change have on Scotland?

As Scotland’s environmental regulator, SEPA plays a key role in gathering, measuring and reporting on factors that affect the environment and, significantly, climate change.

The report on the state of Scotland’s environment, published in 2006, identified a number of areas which will potentially be affected by any change to Scotland’s climate. More recent information is also available from the UK Climate Projections 2009.

Temperature Scotland's temperature records indicate a recent and rapid warming trend, with average spring, summer and winter temperatures rising by just under  1°C between 1961 and 2006. From 1961 to 2011 there was a reduction of 21 days in the number of days of frost (both air and ground frost) annually. As a result, the growing season has also begun earlier and has increased by around 30 days.

We are the hydrometric authority for Scotland and we monitor rainfall and river flow at hundreds of sites across the country.

Scotland has become much wetter since 1961, with the average annual precipitation rate up by 27%.

Winter precipitation (total rainfall and snowfall) has risen in the north and west by 51% and 45%, and high flow frequencies in western rivers have increased.

Marine environment
The seas around Scotland have warmed by up to 1°C over the last 20 years. Warmer seas have prompted changes in the composition, abundance and distribution of a number of marine species, including plankton, fish, sea birds, whales, mammals, dolphins and porpoise.

Sea level is rising all around the UK coastline. All Scottish mainland gauges have recorded a sea level rise over the long term, with the longest individual record at Aberdeen indicating a rise in sea level of 60mm since 1920 . The recent 2013/14 winter also highlighted our vulnerability to possible increased storminess in the North Atlantic leading to increased risk of coastal flooding. We are a sponsoring partner to the Marine Climate Change Impacts Partnership , which provides planning advice to cope with the challenges and opportunities presented by the impacts of climate change in the marine environment.

Predicted impacts
The speed and impact of climate change will be become more severe if we remain heavily dependent on fossil fuels. Indeed, temperatures in Scotland may rise by up to 4°C by the end of this century, with consequences including milder and wetter winters, hotter and drier summers, more extreme weather events and rising sea levels.