Venture capital investment in clean tech firms for the first half of the year tops $4bn

Measurement, reporting and verification dominate "frank discussion" between major economies

Helium-powered ships could be carrying freight – and even passengers – in as little as a decade's time

South Korean conglomerate announces plan to invest more than $14bn in developing low-carbon technologies

Rooftop solar firm follows $100m PG&E deal with fresh funding round

New subsidies aim to drive demand for over 70 fuel-efficient models

Officials confirm some clean-up work has been suspended

New Zealand will launch its emissions trading scheme tomorrow, despite fears over rising energy bills

Everyone's happy, even the Carbon Trust