Islands the world over are becoming over-run with introduced weeds. Some 400 invasive plant species have been identified in a new study of 30 island groups across four oceans, and about half now dominate their new habitat.

The Canadian Government is adjusting its climate plans to more closely resemble those proposed in the US, replacing proposed “intensity targets” with a cap-and-trade system, according to a leaked report on government plans.

Saskatchewan has a problem with its neighbouring Canadian province of Alberta: the oilsands industry. An estimated 70% of emissions from oilsands plants blow into Saskatchewan, causing acid rain to fall on pristine lakes and rivers – and environmentalists want government to put a cap on it.

Renewable energy generation hit a new high in the US in May, with 13% of all power (some 40 million Megawatt hours) coming from renewable sources. Total generation was down 4.1% on the previous year.

Get Celsias headlines on Twitter: Celsiastweets