LONDON — A string of demonstrations that blocked bridges and major streets in central London, disrupted train services and saw over a thousand people arrested are being declared a success in forcing climate change higher up the political agenda.

Extinction Rebellion, a protest movement calling for the prevention of ecological collapse that launched in the United Kingdom last year, has inspired the support of thousands across the country, raised more than £250,000 ($322,000) in just 10 days and gained the attention of…