Do you need readily accessible evidence of the benefits of investments that improve the environment?

Try taking a look at Natural England’s recently published second version of Microeconomic Evidence for Benefits of Investment in the Environment (MEBIE2)1.

MEBIE2 provides a readily accessible summary of evidence of the benefits of improvements in the environment. It also explains the link between the benefits and the improvements and gives an overview of limitations and uncertainties, providing a well-rounded understanding of the issues concerned. The evidence meets Treasury Green Book standards for economic evidence, so it can be used with confidence. It can be used to demonstrate the weight of evidence concerning the benefits of an environmental improvement, and provides case studies that can be used for illustrative purposes.

Compared with the previous version, evidence in MEBIE2 has been extensively revised. The report incorporates new evidence, includes new chapters and employs a simpler format. The review is not exhaustive though and new evidence is continually emerging.

Some examples of information provided in MEBIE2 on issues relevant to urban areas are provided below.

Temperature regulation:

In summary, urban centres can become significantly warmer than surrounding countryside, particularly at night. During heat waves in August 2003 and July 2006, night time temperatures in London were 6-9 degrees Celsius higher than those in rural locations south of London (Greater London Authority 2006). The Urban Heat Island effect is caused by the large area of heat absorbing surfaces, high energy use and reduced wind speed (Bolund and Hunhammar 1999) and leads to night-time temperature remaining high, increasing human health risk (Kovats 2008).

Examples of evidence on the temperature regulation benefits of green infrastructure:

Green infrastructure makes a number of important contributions to local climate regulation. Watery areas can help to stabilise temperatures. A single large tree can transpire 450 litres of water in a day which uses 1000 mega joules of heat energy, making urban trees an effective way to reduce urban temperature (Bolund and Hunhammar 1999).

Hall, Handley et al. (2012) found that a 3.7 percent increase in tree cover in Manchester, which would be possible given existing buildings, roads and other structures, could prevent increases in local temperatures of between 0.5 to 2.3 degrees Celsius by 2080.

Mental health:

Mental health is a major health issue in England with a strong negative impact on the economy. Tackling chronic stress is important because it plays a major role in the causation and development of common physical and mental illnesses, and the problem has been intensifying in recent decades (Health Council of the Netherlands 2004).

Urban street tree (Rebecca Clark)
Urban street tree (Rebecca Clark)

Examples of evidence of the mental health benefits of people’s exposure to nature and green space:

There is strong evidence, from a large number of high-quality studies that nature promotes recovery from stress and attention fatigue, and that it has positive effects on mood, concentration, self-discipline, and physiological stress (Health Council of the Netherlands 2004) [for examples see (Kaplan and Kaplan 1989); (Berman, Jonides et al. 2008), (Ulrich 1984) and (Ulrich, Simons et al. 1991)].

In healthy people, the stress hormone cortisol is at its peak level in the morning and declines during the day. The rate at which it declines reflects the level of stress the person is exposed to throughout the day (less stress results in a faster rate of decline). An exploratory study of disadvantaged residents of Dundee, UK, found that people living in areas with more green space had cortisol levels in their saliva which declined significantly faster than in those people with less access to green space. The same people also reported lower levels of self-perceived stress (Ward Thompson, Roe et al. 2012).

MEBIE2 can be downloaded in its entirety or as individual chapters at

For further information about MEBIE2 please contact Tim Sunderland (

(Article by Rebecca Clark, Natural England).


First published in CJS Focus on Urban Environment in association with Love Parks on 24 November 2014