As it happened: our experts answered your questions about crucial climate summit Cop26

We are still receiving your excellent questions but I’m afraid we’re going to have to wind up the Q&A now. Many thanks to our amazing panellists for giving their time, and to you the readers for, as ever, keeping us on our toes with some incisive and probing questions.

Q: Why the preference for wind turbines over tidal turbines? As long as the moon orbits the earth, we have tides and the UK has a lot of coastline and some strong tides. Moreover, power generation is predictable. It’s a permanent source of energy. Why are we so slow to exploit it?

Professor Mary Gagen replies: Broadly, size of investment, the structure of our subsidies, the environmental impact and, always the elephant in the room with renewables, the grid. In terms of environmental impact floating offshore wind reduces impact on the marine environment and is often mentioned favourably by marine scientists. Tidal stream energy is also at a relatively early stage of development compared to wind and that is seen to limit its commercial competitiveness.

Fiona Harvey adds: Tidal power has proved more difficult technologically, not least as the turbines need to be under the sea and so more difficult to get at for maintetnance and subject to erosion and other problems. Siting tidal power schemes has also been controversial.

Q: With the absence of China and Russia, is COP 26 still a worthwhile exercise? J Smith, South West, UK.

Professor Saleemul Huq replies: both China and Russia will be represented in COP26 for the full two weeks of the COP. The presence of their leaders is not at all essential for the outcomes of the COP. Their presence is really a PR exercise for Boris Johnson to have a photo opportunity only!

Q: Why isn’t a consumer carbon tax isn’t talked about more as a fairly simple way to incentivise consumers to demand and only buy green products? Our problem is not with fossil fuel producers – it is with the consumers of it. It is a very much a demand-side problem. After all, if nobody bought gasoline the oil companies would disappear. Scott Werden, 70 retired physicist, Ha’iku, Hawaii, US.

Lucy Siegle replies: I think this is an interesting question and there are some clues in the EU Green Deal and work around the taxonomy for green products. It’s hard not to consume petroleum products, because as an industry oil and gas infiltrates every part of the market from fashion textiles to healthcare products. By and large these are also cheaper as the market is skewed and the pollution and emissions are famously externalised – plastic fashion products for example are not charged for the non biodegradable waste they become or for any microplastic pollution they cause throughout their lifetime. A green tax on unsustainable products would price in this externalised pollution.

We have to be careful though. Manufacturers using limited life cycle analysis will insist these products are better for the environment on a pound for pound carbon basis and over emphasise the moral hazards of switching to other materials. The answer to this is to standardise the methodology around how you work out what is a sustainable product is and stop trade bodies lobbying!

We’re nearly done for the day – just picking up a few last questions which are still coming in thick and fast!

By the way don’t forget to sign up for our new environment newsletter, Down to Earth which will launch on Thursday! Very exciting.

Q: What will COP26 be aiming to achieve on boosting capacity to adapt to climate change – the often forgotten sibling to reducing emissions- and how likely is it to meet its aims?

Professor Mary Gagen replies: Keep an eye on November 8^th which is ‘adaptation day’ at COP – a day of discussions around climate adaptation, loss and damage. That day will be about how the practical solutions needed to adapt to climate impacts, loss and damage can be delivered. Finance will be critical to adaptation and a major goal for COP is to sort out climate financing from the developed world, which currently runs at 20 Million Dollars a year under budget. A key goal is to ensure at the end of COP26 the climate finance commitment of $100 Billion per year from public and private finance is met. Funding is critical so that developing nations can do things like leapfrog over fossil fuel energy reliance and develop sustainably with renewables in place whilst they grow.

Q: What in your view are the MOST effective action(s) that grassroots organizations can now take to pressure fossil fuel extraction industries and the governments that support them? Jennie, North Carolina, US

Hannah Martin replies: There has been some incredible organising against fossil fuel infrastructure all over the world for many years. Indigenous communities have been leading the fight in North America against tar sands and oil pipelines for decades and local communities have been fighting fracking in Poland, Australia and the UK just as a few examples. Many of these fights have been led by either local communities or those at the sharp end of the pollution and devastation which fossil fuel projects bring to the local environment.

Inspired by these movements we should all be stepping up and supporting our local fights against fossil fuel infrastructure – in the UK at the moment there is a huge fight in trying to stop the new Cambo oil field in the North Sea. Check out the Stop Cambo campaign and sign up to find out how you can get involved!

And Lucy Siegle adds: An effective action remains to move your money. Check your investments, check your pension and divest from fossil fuel to renewables across the board. If you don’t have any money, use your influence (and everyone has this) to get others to move theirs.

Q: On an individual level, what would have more environmental impact: giving up air travel, or giving up eating meat? Or even reducing either of the above by, say, 90%, with individuals rationed to, say, one flight per year and/or meat once a fortnight?

Damian Carrington replies: This study ranks the carbon savings of individual actions of people living in rich nations as follows: Living car-free (2.4 tonnes a year saved), avoiding one transatlantic return flight (1.6T), buying green power for your home (1.5T), eating a plant-based diet (0.8T). It also suggests that by far the biggest action is having one fewer child, though that claim has attracted some criticism. But don’t forget, we need systemic change so that the right choice can be the easy and cost-effective choice for all individuals.

Q: What are the best trees to plant for maximising carbon sequestration? What role does tree age play? How important is it that we know the fate of any felled timber? Lorraine, North Wales

Professor Mary Gagen replies: This is such an important question for the UK because we’ve got ourselves in a bit of a mess with tree planting in the past and we are well below our planting targets. The best thing you could plant just to lay down carbon is a fast growing conifer, like a spruce, in a monoculture plantation. Unfortunately, this is absolutely the worst thing you could do for biodiversity and nature and for the long term stability of our environment. We’re getting much better at planting the right tree in the right place, for the right reasons, but we do need a mosaic with sensible planting of timber, native woodland protected and restored and the preservation of our urban woodland as well.

Q: What will world leaders do right now to create the infrastructure necessary to reduce global dependency on automobiles? T-M Baird, Vermont

Damian Carrington replies: This comes down to prioritising pedestrians, cyclists and public transport over motorists when developing, or redeveloping, urban areas. In many places cars, and their parking spaces, dominate. But change is happening, for example, in Bogota, Colombia, where there was a concerted effort to create a city “with more public space for children than for motor vehicles”, and in Pune, India, where a road redesign prioritised pedestrians and cyclists by building wide sidewalks and children’s play areas. You can read more here. Another example is the increase in cycle lanes – 1000km more in Europe in 2020. As well as climate concerns, the rising awareness of the huge harm caused by air pollution is also driving change.