Ecomodernism launch was a screw-up of impressive proportions

Our attempt to launch a new environmental political movement in the UK was certainly ill-timed but is hopefully not doomed

Bright lights, big trees: Dutch designer imagines an ‘urban forest’

City links: Blueprints for a neighbourhood of tree houses and smiley-face signals to reduce road rage feature in this week’s best city stories

UN climate chief says the science is clear: there is no space for new coal

Christiana Figueres says Australia needs a national consensus to achieve maximum effort in fight to avoid dangerous climate change

Is being vegan the most ethical way to live?

Reducing meat consumption is important, but going vegan may not solve all our problems…

If you have an ethical dilemma, email Lucy at lucy.siegle@observer.co.uk

Green news roundup: mega droughts, geoengineering and straw homes

The week’s top environment news stories and green events. If you’re not already receiving this roundup, sign up here to get the briefing delivered to your inbox

Solar power drives renewable energy investment boom in 2014

Global clean energy investment leapt 16% in 2014 led by solar power surge in US and China – but Europe lags behind