Green light: Purple herons, oil spill clean-up and a garden biobliz

Oil spill The scale of disaster unfolding in the Gulf of Mexico became apparent this week as the no-fishing zone doubled and controversial dispersant was used. As insurers warned of price hikes with losses heading for $3.5bn , BP claimed it was slowing flow of oil and Guardian readers suggested their own ideas for capping the spill . Natural world For once, a slew of good news: a campaign to save ancient trees in London got underway , purple herons nested in the UK for the first time and Kew rescued the world's smallest waterlily from extinction . Meanwhile, Juliette Jowit undertook a 'bioblitz' at her home to investigate the secret life of a suburban garden and Stuart Hine of the Natural History Museum wrote about how natural history was moving out of draughty church halls to thrive online . Climate change Speculation over who would replace Yvo de Boer at the UN's climate secretariat came to an end this week - Costa Rican Christiana Figueres will become the new UN climate chief on 1 July. Around the world, efforts to mitigate climate change included a plan for Cornwall's 'Silicon Vineyards' aim to triple solar capacity in UK , a step closer to reality for the UK's first mass market electric car and a pledge by David Cameron to make his coalition the 'greenest government ever' . Joss Garman reflected on the crucial role of activism in scrapping Heathrow's third runway. Multimedia Pinocchio frogs, tame wooly rats and the world's smallest wallaby are among the weird and wonderful cast of new creatures discovered on the Indonesian island of New Guinea this week. You can see them all in our gallery . Back in the UK, an audio slideshow shows what a bioblitz looks and sounds like in a British garden and Guardian readers shared their dazzling photos of bluebells . In the US, new photos show what's happening on the coast as the oil hits land. Green living Join Leo Hickman to help him answer whether British or imported strawberries are worse for your carbon footprint and find out whether you can use dry cleaners and still be green . Lucy Siegle also looked at an attempt to harness 'pavement power' . Best of the web Andrew Williams argues bonuses can be a good thing - if they're linked to carbon emissions . Elsewhere, BusinessGreen ran a quirky story about Sony's energy saving TVs which watch you while you sleep and SolveClimate had news of an International Energy Agency report that suggests the US could become leader in desert solar . For more of the best environment comment and news from around the web, visit the Guardian Environment Network . ...And finally Nearly a quarter of UK adults can't identify one of Britain's most common trees, says the Natural History Museum. But could you do better identifying British wildlife? Try our quiz