In 2010, our carbon footprint was 19,300 tonnes (2009: 13,700 tonnes).

This increase in our reported carbon footprint was due to significant improvements in data comprehensiveness and accuracy, combined with the inclusion of the first full year of data for the former Brixton portfolio which was acquired in August 2009.

Since 2009, our carbon reporting has encompassed emissions from the energy that we purchase both for our own use and on behalf of our occupiers. This data is helping us to identify opportunities to save energy, cut utility costs and prepare for increasingly stringent regulation and environmental taxation such as the UK Government's CRC Energy Efficiency Scheme.

We have participated in the investor-led Carbon Disclosure Project since 2007, ranking third amongst UK Real Estate Investment Trusts in 2010, with a score of 73 per cent, up from 65 per cent in 2009. We use the Greenhouse Gas Protocol methodology to calculate our carbon footprint.

95 per cent of our 2010 carbon footprint related to energy use across our portfolio, 4 per cent related to energy use in the offices we occupy and 1 per cent to business travel.

At Energy Park Vimercate near Milan (pictured), we are targeting a LEED Silver environmental rating for our new buildings, with 37 per cent lower forecast carbon emissions and energy bills than standard buildings, thanks to sustainability initiatives such as ground-source heating and cooling.