It is no surprise that the government’s strategy on fracking has been deemed unlawful, write Robin Russell-Jones and Geraint Davies . Carbon emissions will be even lower if the gas boiler is run on hydrogen gas, writes Carl Arntzen . And Stephen Martin and Stephen Sterling say wealth redistribution is needed to reduce global warming

It is no surprise that the government’s strategy on fracking has been deemed unlawful (Fracking guidance illegally ignores climate change, 7 March). Gas may be more fuel efficient than coal when burnt, but shale gas is 95% methane, and methane is a powerful greenhouse gas. According to the IPCC it has a global warming potential (GWP) 85 times greater than carbon dioxide over a 20-year timeframe. Misleadingly, HMG have relied on an obsolete figure of 36 for the GWP of methane, dating back to 2013.

Methane levels plateaued in the late 1990s, but have started to increase again over the past decade and have now reached 1,900 parts per billion, against a pre-industrial level of 700. Fracking is the obvious culprit. Satellite data over the US has shown that methane leakage exceeds 5% of shale gas production, an observation that fits with more recent studies by Nasa showing that fossil fuels are the major contributor to the continuing rise in atmospheric methane.

Despite this evidence, the government’s energy strategy is to forge ahead with fracking while reducing environmental safeguards and providing tax incentives for its development. The government claim that gas is better than coal from a climate change perspective is only sustainable if fugitive emissions of methane are ignored. Let us hope that the high court judgment means that fracking will be abandoned in the UK as it has been elsewhere in Europe.

Dr Robin Russell-Jones Scientific adviser to the all-party parliamentary group on air pollution (APPG)

Geraint Davies MP Chair, APPG

• Although I agree that climate change needs to be tackled, it is too simplistic for the Committee on Climate Change to suggest not connecting all new-build schemes to the gas grid from 2025 (Call for ban on gas hobs and boilers in new homes by 2025, 21 February). If the committee gets its way and all new builds are off-gas, then electricity for solutions such as heat pumps still needs to come from somewhere. Unless the electricity comes from a zero-carbon source, it defeats the object. If the whole of the country came off gas, we would need the power of about 30 nuclear power stations, and currently we have eight! Also, if we do switch to hydrogen gas then these homes without a gas connection could not be connected in the future and would miss the other benefits that hydrogen gas could deliver such as carbon-free cooking.

The Department for Business, Energy and Industrial Strategy (BEIS) has already acknowledged that there is no one-size-fits-all answer to the decarbonisation of heating. Instead, different solutions should be working together. A hybrid system that uses a heat pump up to a certain temperature, which is then supported by a gas boiler, would be very effective not only in new build but many existing homes as well.

Carbon emissions will be even lower if the gas boiler is run on hydrogen gas. Instead of advocating for unreasonable promises from government, the CCC should be supporting the research that is already under way into new “no carbon fuels”. I’d even like to extend an invitation to the CCC’s chief executive, Chris Stark, to a prototype demonstration we have planned later in the year, where we will show how a 100% hydrogen boiler will run.

Carl Arntzen

CEO, Worcester Bosch Group; chairman, the Domestic Heat Strategy Group

• Our unsustainable lifestyles and commitment to perpetual economic growth have become the major drivers of climate change. Jason Hickel suggests that the solution is “about changing the way our economy operates” (Climate breakdown is coming. The UK needs a Greener New Deal, theguardian.com, 5 March).

Encouragingly, the UN sustainable development goals (SDGs) form a new roadmap for our future that in principle aligns the economy with the Earth’s life support systems. Yet a recent report by the Stockholm Resilience Centre[1] shows that attempting to achieve the socio-economic goals using conventional growth policies would make it virtually impossible to reduce the speed of global warming and environmental degradation.

The research team tested three other scenarios and the only one that met all goals was the one that implemented systemic transformational change. A key element in the model was reducing inequality by a redistribution of wealth, work and income, including ensuring that the 10% richest people take no more that 40% of the income. We have an unprecedented and immense challenge before us – with little choice but to engage.

Stephen Martin Visiting professor, University of West of England

Stephen Sterling Emeritus professor of sustainability education, Plymouth University

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