Key Scottish Environment Statistics 2014

Global Atmosphere

Annual Mean Temperature: 1910-2013

Annual mean temperature - difference from 1961-1990 average (degrees Celsius)[1]

The balance between incoming solar energy and outgoing infrared radiation determines the Earth's temperature. Changes in the amount of energy retained within the atmosphere affects global climate, which naturally exhibits long-term fluctuations. However, current climate trends are unlikely to be entirely natural in origin and there is strong evidence that human activities are having a discernible impact on the global climate.[2]

For Scotland, the effects of climate change have implications in areas such as buildings and property, health, agriculture, forestry, transport, water resources and energy demand. These are areas of economic, social and environmental importance.

The globally averaged combined land and ocean surface temperature data as calculated by a linear trend, show a warming of 0.85 [0.65 to 1.06] °C, over the period 1880 to 2012.[2] Similarly, a linear trend through the Scottish land temperature series for the period 1910-2013 indicates an average annual increase of 0.006°C, or 0.6°C every 100 years.[3]

Seven of the ten warmest years recorded in Scotland have all occurred in the 21st century. The warmest years on record are 2003 and 2006, with temperatures of 1.18°C and 1.20 °C above the 1961-1990 average, respectively. The average temperature from 2000 - 2009 was 0.90°C higher than the 1961-1990 average and warmer than any other decade. 2013 shows an increase in mean temperature of 0.2°C from 2012. The 2013 temperature of 7.52°C is 0.49°C higher than the 1961-1990 average.

Temperatures in Scotland are projected to continue increasing over the next century, with a general trend towards hotter summers and milder winters[4]. For example, by 2070 - 2100, projected increase in mean temperature for the East of Scotland in the winter months[5] is 2.2°C (1.0°C to 3.7°C) and in the summer months[6], is 3.5°C (1.8°C to 5.7°C).

Source: Met Office / Metadata

Annual Precipitation: 1910-2013

Annual precipitation as a percentage of 1961-1990 average[1]

The average annual precipitation in the 1980s, 1990s and 2000s was higher than in previous decades, particularly the 1970s, which contained several years with below average rainfall. Annual precipitation in 2013 was 6% above the 1961-1990 baseline. Although there has been an overall increase in rainfall, it varies among seasons and regions.[3]

The average winter precipitation in the 1990s and 2000s was around 23% higher than the 1961-1990 baseline for winter precipitation, compared to the 1960s which was around 9% lower. In 2013, the winter precipitation was 13% greater than the baseline. Summer precipitation has not differed as much; average summer precipitation in the 1990s was 4% below the 1961-1990 baseline for summer precipitation and in the 2000s was 15% above the baseline. In 2013, summer precipitation was 17% lower than the baseline.[7]

Climate change will have an impact on Scotland. The UK Climate projections for the next century indicate that the climate trends observed over the last century will continue and intensify over the coming decades. Rainfall is likely to become even more seasonal, with an average summer becoming drier, while autumn and winter become wetter[4]. For example, projected changes in the East of Scotland are reduced precipitation of 17% (-33% to 0%) in the summer months[6] and an increase of 12% (1% to 25%) precipitation in winter months[5]. Precipitation changes have several implications for Scotland, affecting water resources, flood and drought risk and habitat loss.

Source: Met Office / Metadata

Greenhouse Gas Emissions by Source: 1990-2012R

Values in million tonnes carbon dioxide equivalent (MtCO2e)[8]

It should be noted that improved data sources and estimation techniques have routinely led to revision of historic greenhouse gas emission estimates. All data has been revised to reflect these changes.

Greenhouse gases (GHGs) in the atmosphere help to retain radiative energy, resulting in warming of the lower atmosphere and earth surface. Atmospheric concentrations of GHGs have increased as a result of human activities since the Industrial Revolution (c.1750). This has enhanced the greenhouse effect and is influencing global climate change.[9]

Scotland's emissions of greenhouse gases in 2012 were estimated to be 52.9 million tonnes of carbon dioxide equivalent (MtCO2e), 0.8% (0.4 MtCO2e) higher than 2011 and 29.9% below 1990 levels[8]. The main contributors to this long term reduction have been a fall in energy supply emissions (such as in the production of electricity) and from business and industrial emissions[10],[11],[12].

In 2012, Energy supply was the largest source of net emissions (17.1 MtCO2e), followed by agriculture and related land use (11.2 MtCO2e), and Transport (excluding International Aviation and Shipping) (10.5 MtCO2e). Emissions from the energy supply sector were greater than emissions from public sector, development, international aviation and shipping, waste management and residential emissions combined. Forestry was the only aggregate sector in which there has been a net emissions sink (removal of 9.9 MtCO2e).

Most sectors exhibit a general downward trend between 1990 and 2012, most clearly evident since 1998. In all years, energy supply is the main source of greenhouse gas emissions. Energy supply is a very volatile sector, which is linked to the ambient temperature, particularly during the winter months; and fuel used for electricity production, which in turn is largely driven by the price of coal relative to "cleaner" fuels[13],[14].

Source: National Atmospheric Emissions Inventory / Scottish Government / Metadata

Reporting against Scotland's Climate Change Targets. Greenhouse Gas Emissions Adjusted to Take Account of Trading in the EU Emissions Trading System: 1990 base year - 2012R

Greenhouse gas emissions taking account of emissions trading (MtCO2e)[8],[15]

It should be noted that improved data sources and estimation techniques have routinely led to revision of historic greenhouse gas emission estimates. All data has been revised to reflect these changes

The European Union Emission Trading System (EU ETS) is the largest multi-country, multi-sector, company-level, greenhouse gas (GHG) emission trading system world-wide[16]. When trading in the EU ETS is taken into account, Scottish GHG emissions, including international aviation and shipping, increased by 0.5% between 2011 and 2012 (from 55.4 MtCO2e to 55.7 MtCO2e). Compared with the 1990 baseline, such emissions in 2012 were 26.4% lower.

The Climate Change (Scotland) Act 2009[17] sets a statutory framework for greenhouse gas emissions reductions in Scotland with a reduction target of at least 80 per cent by 2050 and an interim reduction target of at least 42 per cent by 2020, both reductions against the 1990 baseline[15]. The Act also requires Scottish Ministers to set annual targets for emissions and the Scottish Parliament has passed legislation setting annual targets to the year 2027[18], [19]. The 2012 target is 53.226 million tonnes of carbon dioxide equivalent (MtCO2e). The fixed annual targets were based on data from the 1990-2008 Greenhouse Gas Inventory. The Greenhouse Gas Inventory has been revised upwards since then, increasing the percentage reductions required to meet the fixed annual targets. In accounting for trading in the EU ETS under the Climate Change (Scotland) Act 2009, the approach taken is to set contributions from Scottish installations in the EU ETS equal to Scotland's share of the UK's EU ETS cap[20] (Scotland's cap).

These figures are also used for reporting progress against the Scottish Government's Sustainability Purpose Target[21] and is one of the indicators set out in 'Low Carbon Scotland: A Behaviours Framework'[22].

Source: National Atmospheric Emissions Inventory / Scottish Government / Metadata

Scotland's Carbon Footprint (Greenhouse Gas Emissions on a Consumption Basis): 1998-2010

Values in million tonnes carbon dioxide equivalent (MtCO2e)[8]

The carbon footprint refers to greenhouse gas emissions that are associated with the spending of Scottish residents on goods and services, wherever in the world these emissions arise along the supply chain, and those which are directly generated by Scottish households; for example, through heating and private motoring. The Carbon Footprint is part of a small set of low carbon attitude and behaviour-related indicators set out in 'Low Carbon Scotland: A Behaviours Framework'[22].

Scotland's carbon footprint can be separated into a number of components: those generated directly by Scottish households through heating and private motoring, those emissions relating to goods and services produced by UK business, and those emissions relating to imported goods and services. These are often referred to as emissions that are "embedded" in imports.

Between 2009 and 2010, Scotland's carbon footprint increased by 4% following a 19% fall in 2009. From 1998, the footprint rose by 15% to a peak of 101.1 million tonnes carbon dioxide equivalent[8] (MtCO2e) in 2007 before falling to 78.7 MtCO2e in 2009. In 2010, Scotland's carbon footprint was 82.2 MtCO2e, 6% less than in 1998 (87.9 MtCO2e).

Source: Scottish Government / Metadata

Column Ozone Measurements: 1981-2013

Column ozone concentrations over Lerwick (Dobson units)

The stratospheric ozone layer, located around 10-30 km above the Earth's surface, forms a protective shield against harmful solar (UVB) radiation.[23] Thinning of the ozone layer has occurred since the beginning of the 1980s in all regions except those around the equator.

Depletion is most marked in Antarctica where, in 2013, the area of the ozone hole reached a maximum of 24.0 million km2 (over 300 times the land area of Scotland) on 16 September. This is more than in 2012 and 2010, but less than in 2011. If one considers the last 20 ozone holes (1994-2013), fifteen ozone holes have seen more ozone loss and four have seen less ozone loss than the 2013 ozone hole.[24]

The 1987 Montreal Protocol[25] set guidelines to eliminate the global production and use of ozone depleting substances. European production of CFCs for non-essential use fell to zero in 1995. However, leaks form old equipment and the long life of these substances mean that full recovery of the ozone layer is not predicted until about 2050.

The total ozone levels at Lerwick vary seasonally, with maximum levels generally occurring in early spring and minimum levels in autumn. Over the last 30 years, the annual average total ozone cover over Lerwick has shown the natural variability which would be expected due to varying meteorological conditions. Generally, levels decreased until the late 1990s. More recently, it appears that this trend may be levelling out, but it is too soon to be sure.

Source: DEFRA / Metadata