Speed hump cuts 'daft', safety groups say per BBC News

The BBC report http://www.bbc.co.uk/news/uk-politics-40788674 on safety groups opposition to removing speed humps. Apparently:

'Ripping up speed humps to combat air pollution is "daft and irresponsible", road safety campaigners have said.

They are writing to ministers to warn that removing speed bumps will actually increase danger to children.

The government said it would fund councils in England to tear out humps because they elevated pollution as drivers surged between them.

Campaigners say the risk of accidents from speeding drivers almost certainly outweighs the long-term pollution risk.'

Two thoughts on this:
First, have accident rates increased in the London Borough of Barnet since the Conservative Council removed all speed humps across the borough some years ago? Might some facts be useful in this debate or would the campaigners prefer feelings to facts?
Second, I thought that the lefty narrative was that global warming / climate change was the biggest threat to humanity. Was that just not true?