The Big Questions: How do we make cycling safer? What are the lessons of the Paul Flowers affair?

What is your response to the Campaign to Protect Rural England coming out in favour of fracking?

Surprise. Although given the qualification that it wants it restricted to brownfield sites, of which there’d be few, not too worried. I’m confident we won’t see significant fracking in Britain. We need to work out how to leave more than half of our known fossil fuel reserves in the ground to avoid catastrophic climate change, not go looking for more. That might seem simple – just don’t dig – but there’s the “carbon bubble”. Our share markets are underpinned by valuations of fossil fuel reserves that can’t be used.

The World Forum on Natural Capital thinks that the way to protect the environment is to give it a financial value. Do you agree?

No. That suggests that we could trade off bits in return for cash, when it is genuinely invaluable. It’s worth reflecting that our economy is an entire subset of our environment – our lives are entirely dependent on it. We need every bit of healthy soil, clean water and diverse species that we haven’t yet trashed or lost. We’ve already so depleted the Earth that to feed and clothe ourselves and to have a liveable climate we have to protect every scrap of what we haven’t yet trashed, and restore lost treasures where we can.

Downing Street says it “does not recognise” reports that David Cameron told aides to “get rid of all the green crap” from energy bills. But does the quote ring true from the Prime Minister who promised “the greenest government ever”?

It’s interesting that this came from a Tory source in a Tory-friendly newspaper. It shows Mr Cameron is rattled, both by the struggle of more households in trying to pay their bills in our low-wage economy, and his party’s “millionaire Etonite” image problem. But it does give us a headline-friendly dismissal of the “greenest ever” claim, which has become a sad, sick joke. This zombie road-building, would-be greenbelt-destroying, shale gas-loving, renewable energy-resistant government deserves many labels.

How else – apart from by reducing environmental subsidies – can energy bills be lowered while still investing in necessary infrastructure upgrades?

There’s one huge area of action missing – energy conservation. The Energy Bill Revolution campaign has calculated that taking the income from carbon taxes and putting it into treating our leaky, hard-to-heat homes would lift nine out of 10 households out of fuel poverty, create up to 200,000 jobs and cut greenhouse gas emissions. That wouldn’t just cut bills temporarily, but permanently. Combine that with investment in renewable energy through community ownership, and a smart grid that manages demand as well as supply, and you’ve got a plan for a secure, environmentally friendly, affordable energy future.

What are the lessons to be learned from the debacle over Rev Paul Flowers?

First, it’s worth noting that this happened in what was actually a private bank that happened to be owned by a co-operative, so this shouldn’t stand against the advantages of co-operatives in general. But it is clear that we still don’t have any kind of handle on our financial sector. This scandal is a stark reminder of the need to scrutinise each and every bank. The industry has been able to say that continuing revelations of market rigging, mis-selling of products and the Bernie Madoff fraud relate to events before the financial crash. This claim came after.

Did the UN Climate Convention that ended in Warsaw yesterday do what it needed to do?

Sadly, no. It’s telling that Greenpeace, Friends of the Earth, 350.org and representatives of indigenous and women’s groups walked out. The influence of the fossil-fuel industries was evident. But we are seeing global progress – President Obama’s climate action plan is a start; the Chinese are getting serious – and the pressure on them to tackle their air pollution crisis will have positive side effects on climate change. Germany and Denmark are showing the possibilities of renewables.

The Government’s plans for new garden cities have stalled, but the Opposition is reviving the idea. What would be your solution to the housing crisis?

We have to stop hoping that private developers will build us out of this crisis. We would focus on building council homes for affordable rent and co-operative homes for genuinely affordable ownership, wherever possible on brownfield sites. We would also aim to ensure renting from private landlords is a stable, affordable option for the many who need it. Long term, we need to rebalance economic opportunities so that we make use of the 200,000 homes outside of London and the South-east that have been left empty for long periods of time.

Six cyclists have died in London in the past two weeks. What is the problem and what is the solution?

The problems are streets designed and run for the maximum benefit of motorised road users, at the cost of the safety of pedestrians and cyclists; HGVs and large lorries where they have no need to be; inadequate safety provisions on those lorries; excessive speed; and a legal framework that should be especially protective of vulnerable road users. Solutions: ban unnecessary HGVs and large lorries; ensure those remaining have all possible safety measures, cut speed limits, introduce strict liability, improve driver education and enforcement.

Monty Python are re-forming. Who else would you like to see stage a comeback?

Redgum, an Australian folk/rock band. Their anti-Vietnam War song “I Was Only 19” could be updated for the Afghan/Iraq wars, and their “One More Boring Night in Adelaide”, about discrimination against Aborigines, could be reshaped to mark the struggles of migrants. And hearing them would make me feel 18 again.

Natalie Bennett is the leader of the Green Party of England and Wales