GLASGOW, Nov 2 (Reuters Breakingviews) - Joe Biden and Ursula von der Leyen’s green steel pact has important lessons for COP26. The bilateral deal struck by the U.S. president and his European Commission counterpart on the eve of Glasgow’s global climate shindig may just sound like an overdue reversal of Trump-era excesses. But it’s also a decent template for decarbonising economies. On the face of it, the agreement merely reverses Donald Trump’s obstreperous 25% tariff on European Union steel imports, against which Brussels promptly retaliated. But it adds a vital green kicker. The two sides will reduce mutual tariffs, but retain them on imports from other states which fail to hit standards for low-carbon steel production. Those details are currently being fine-tuned. The pair are well placed to apply pressure. A decent chunk of their domestic production stems from electrically powered furnaces burning scrap metal. These emit far fewer greenhouse gases than the carbon-belching blast furnaces that produce most Chinese steel. The United States, Germany and Italy are also the world’s three biggest steel importers, while China accounts for half its production. Coordinated pressure by buyers could thus lead to significant emissions reductions in a sector that pumps out 3 billion tonnes of carbon dioxide a year, not far off 10% of humanity’s total. In one sense, the pact looks frustratingly unambitious. The EU’s preferred modus operandi, reiterated on Monday by von der Leyen, is an all-encompassing price for carbon. To counter the risk of European companies moving factories outside the bloc, Brussels is pushing for a carbon border levy that imposes this price on foreign imports read more . On paper, it’s an elegant solution. In the real world, however, such a deal will be hard to get U.S. lawmakers to support. Besides the complexity, it smacks of Europe telling America what to do. Hence why even a green champion like former Secretary of State John Kerry was cool on the idea earlier this year. The new deal will define what green steel looks like, but allow Biden to get there by regulatory standards and von der Leyen to use carbon pricing. Given that the planet needs to halve carbon emissions by 2030, compromise in favour of quick wins is preferable to holding out for universal agreement. Follow @gfhay on Twitter CONTEXT NEWS - The United States and the European Union on Oct. 31 announced a commitment to negotiate the world’s first carbon-based sectoral arrangement on steel and aluminium trade by 2024. - In 2018, former U.S. President Donald Trump imposed tariffs of 25% on steel and 10% on aluminium from the EU, as well as China, India, Russia and Switzerland. Under the new agreement, to run for two years, the Trump-era tariffs will remain but only for imports of the metals exceeding set quotas. - The deal should also end EU retaliatory tariffs on U.S. products ranging from bourbon whiskey to Harley-Davidson motorbikes. The EU had planned to double many of the tariffs in December. - The transatlantic partners will spend the next two years working on a deal to address overcapacity, above all for steel and mainly centred on Chinese production, and efforts to make those industries more environmentally sustainable.