buy 100% of our electricity worldwide from renewable sources, wherever markets allow. We will continue to work with others, such as RE100 and WBCSD, to drive the creation of a global market for renewable power, engage with policymakers and governments to support policies in this area and share our knowledge and experience to encourage others to make the switch, for example through international fora, but also through employee, customer and supplier engagement campaigns.
help our customers reduce carbon emissions by at least three times the end-to-end carbon impact of our business. We will do this through our customers using our products and services which help them reduce their need for travel, reduces energy use and reduces amount of materials and manufacturing. We are currently at a ratio of 2.2:1 and these services represent 22%, or £5.bn, of BT’s total revenues. These services represent 22%, or £5.bn, of BT’s total revenues. In 2017/18, our products and services helped customers avoid at least 11.3 million tonnes of CO2e.
in line with our new 1.5 degree Celsius science-based target, cut our Scope 1 and 2 carbon emissions intensity by 87% against a 2016/17 baseline and the carbon emissions associated with our supply chain by 29% in the same timeframe.
We will continue to roll out our pioneering contract clause which requires a supplier to reduce carbon emissions and energy consumption over the term of their contract with BT.