A new report from Pike Research forcasts good news for renewable energy and mobile base stations (the wireless communications station used to connect cell phone networks). Clean energy will power 4.5% of base stations by 2014, and while that doesn't sound like much, it's a boost up from the mere 0.11% in 2010, or a 40.9% increase. But even more exciting is the percentage of base stations powered by renewable energy in developing countries will jot up to 8% by 2014. With mobile phone subscriptions hitting 5 billion worldwide, a boost in clean energy is a big deal for carbon emissions.

The number of mobile subscriptions in the world is expected to pass five billion this year, according to the International Telecommunication Union, a trade group. That would mean more human beings today have access to a cellphone than the United Nations says have access to a clean toilet.

Some cellphones emit several times more radiation than others, the Environmental Working Group found in one of the most exhaustive studies of its kind.

The government watchdog group on Wednesday releases a list ranking cellphones in terms of radiation. The free listing of more than 1,000 devices can be viewed here.