US President Donald Trump has announced the reversal of the so-called endangerment finding, a key Obama-era scientific ruling that underpins much of US environmental legislation. As a result of this, experts are predicting various environmental and economic impacts, though the decision by the US Environmental Protection Agency (EPA) is expected to be challenged in the courts from environmental groups. Here are some of the potential impacts. 1. Fewer greenhouse gas emissions restrictions: The most obvious outcome is that there will be fewer restrictions placed on greenhouse-gas-producing industries - in particular vehicle manufacturers. The 2009 endangerment finding identified six greenhouse gases as endangering current and future generations. With it gone, so is much of the legal basis limiting US industries' emissions. The Environmental Defense Fund estimates an additional 7.5-18 billion tonnes of greenhouse gases could be emitted by 2055. 2. Cheaper cars in the US (but they'll be harder to export): The Trump administration says removing the finding will reduce automobile manufacturers' costs by around $2,400 per car. However, with climate targets still applicable in many international markets, experts doubt how much car manufacturers will change production and warn that US cars may become less desirable for export. 3. Nuisance lawsuits: A 2011 US Supreme Court ruling placed the power for regulating greenhouse gas emissions with the EPA. With the endangerment finding gone, legal experts predict a surge in "public nuisance" lawsuits, where states or communities could sue corporate polluters for compensation, a practice common before the 2011 ruling. 4. Public health: Announcing the end of the endangerment findings, the EPA stated that maintaining greenhouse gas emissions standards was not a requirement to fulfil its "core mission of protecting human health and the environment." But scientists consistently link greenhouse gas emissions to adverse health effects.