Saving Earth one light at a time

Published online 6 December 2010

Mohammed Yahia


The United Nations Environment Programme (UNEP) claims a complete switch to energy efficient lights in the developing world would reduce about 1% of the global greenhouse gas emissions.

The first Country Lighting Assessments, released during the United Nations Climate Change Summit in Cancún, Mexico, estimates the reduced carbon emissions if 100 countries adopt efficient lighting technologies in place of energy-intensive candescent lamps.

According to the report, part of en.lighten, a UNEP project that aims to promote use of energy saving lights in the developing world, artificial lighting accounts for 19% of global electricity consumption or 6% to 8% of all greenhouse gases emissions.

"The fact is that the world cannot afford to lose any more [energy] due to inefficient technology. And now, even though energy efficient technology does exist or can be quickly made available, such technologies are not applied to sufficient scale yet," said Bernard Jamet, head of the technology transfer unit in the UNEP.

If all Arab states make a complete switch to efficient lighting, the region would decrease its carbon dioxide emissions by more than 16 million tonnes each year. This is the equivalent of shutting 11 medium-sized coal power plants, or taking nearly 4 million cars off the roads.

"It would cost mainly about 3 billion USD to shift all the countries that have not shifted yet," said Jamet. According to the country assessments, China alone could save 5.5 billion USD annually with energy efficient lights

However, a paper published in the Journal of Physics D: Applied Physics1 in August 2010 argues that switching to the cheaper, more efficient light-emitting diodes (LED) lights will not decrease power consumption, but lead to people using more lighting to create brighter atmospheres, keeping electricity use constant.

According to the paper, data reveals that people have historically spent the same amount of money per capita on lighting. Cheaper lights would allow for brighter lights for longer periods of time. While the shift might not decrease greenhouse gases emissions, it would increase productivity, allow more time for education in the evenings and lead to better living standards, especially in poorer communities.

The en.lighten project, with a 20 million USD four-year budget, promotes high performance, efficient lighting technologies and helps participating countries plan the switch. It also aims to help rural communities that do not have access to electricity to replace kerosene-based lighting with more efficient lights, such as solar-powered LED lights.


  1. Tsao, J.Y et al. Solid-state lighting: an energy-economics perspective. Journal of Physics D Applied Physics 43, 354001-354017 (2010) | Article