A top climate scientist has said abolishing behaviour adopted during the pandemic, such as working from home and flying less, would <a href="https://www.thenationalnews.com/Business/UK/2022/01/25/mckinsey-net-zero-transition-will-cost-275-trillion-globally-by-2050/" target="_blank">severely hamper global net-zero ambitions</a>. “We expect transport to return more to pre-pandemic emissions in 2022,” said Pierre Friedlingstein, Mathematical Modelling of Climate Systems chairman at Exeter University. The warning came after the UK government published data showing a significant decrease in emissions in 2020 when the country was subject to <a href="https://www.thenationalnews.com/tags/covid/" target="_blank">Covid-19</a> restrictions, curtailing the freedom to travel and meet up. Overall, UK greenhouse gas emissions in 2020 stood at 406 million tonnes CO2 equivalent (MtCO2e), a reduction of 9.5 per cent from 2019 and 49.7 per cent from 1990. Transport was the most polluting sector but the UK government is placing its faith in a wide-ranging reset of its energy consumption profile. “Moving forward, we are building on the UK’s track record of having decarbonised faster than any other G7 country, by doubling down on our plan to build a strong, home-grown renewable energy sector to further reduce Britain’s reliance on fossil fuels,” a government spokesman told <i>The National</i>. Since the onset of the pandemic, the transport sector saw the biggest percentage of reduction in emissions, but with restrictions easing those gains could snap back. Breaking down transport into its constituent sectors, domestic aviation emissions fell by a precipitous 57 per cent, with the next biggest fall coming from road use, in which emissions dropped by 19 per cent. The reduction in emissions from transport was not a UK-only phenomenon, as much of the world was also subject to equally stringent restrictions. “Transport emissions globally have been massively affected by pandemic, falling around 25 per cent in 2020,” said Prof Friedlingstein. The UK has yet to publish figures for last year, but the first indications are that overall global emissions bounced back to near pre-pandemic levels, with transport the only outlier. <a href="https://www.thenationalnews.com/Business/UK/2022/01/24/uk-airline-bosses-make-new-call-for-end-to-covid-travel-restrictions/" target="_blank">Adhering to Covid-19 rules </a>caused emissions from international travel to fall by 61 per cent between 2019 and 2020. This plunge isn't expected to last. “[A quarter] of the world's <a href="https://www.thenationalnews.com/tags/emissions/" target="_blank">emissions</a> come from transport and there's no clear trend in reduction. But it has to happen," Prof Friedlingstein said. While the need to accelerate the transition to cleaner fuels and develop greener global infrastructures is paramount, Prof Friedlingstein believes at least some of the behavioural changes foisted upon the world by Covid-19 restrictions must endure if net-zero targets are to be reached. “Because of the pandemic, people realise working from home is something we can do,” he said. “Reducing travel and having more and more virtual meetings is also something we can do. I am hoping this trend will continue in the future.” He added that governments must play a role in this transition. “The changes should be incentivised and people made to feel they don't cost too much,” he said. “People are willing to make small changes to save the planet, but governments have to invest to make them acceptable.” Prof Friedlingstein would also like to see an end to ultra-cheap, short-haul flights. To avoid travel becoming the preserve of the rich, he suggested an individual carbon quota might have to be imposed, placing limits on how much people can fly. A UK government representative acknowledged the impact of Covid-19 but didn't draw any behavioural conclusions. Instead, the focus was placed on the UK's technological track record and future aspirations. Prof Friedlingstein, however, sees the focus on technology alone as a missed opportunity. “Lifestyles do change, and you see trends in people such as going vegan or in less consumption of meat. And these have happened over the last 10 years," he said.