US president Donald Trump has begun the process of stripping away the central pillars of the US climate plan put in place by former President Barack Obama.
Watching from New Zealand, this feels like a huge pendulum swing. A few months ago the US was a world leader, investing in climate science and the solutions. Today the White House has reverted to climate change denialism and promotion of the coal industry.
So what exactly has Trump done?
On Tuesday, Trump signed an order instructing his environmental agencies to repeal Obama's Clean Power Plan. This means lifting a ban on new coal mines opening on public land. It means undoing regulations requiring power plants to slowly reduce the amount of climate pollution they emit.
The order also tells officials they can no longer consider climate change when planning major infrastructure projects. Not particularly smart if you're building next to a rising sea.
The US is a global super-polluter, second only to the much more populous China. Having the US go off-the-rails on climate change, for any extended period of time, could be catastrophic.
So what are we in the rest of the world to do?
Political leaders who are already skeptical of climate change might well think if the US isn't going to do anything about climate change, why should we?
To take that position, however, would be a huge mistake. Fortunately many countries, cities, and business leaders realise this and are right now committing to take even stronger action on climate change.
This is because there is growing recognition that climate solutions offer tremendous gains for people's health, the environment, and families' back pockets.
The Clean Power Plan, for example, would have helped to clean up the air and prevent 3,600 premature deaths, 90,000 asthma attacks and 1,700 heart attacks each year.
This improvement to health, alongside environmental gains, was estimated to give a $26-$45 billion economic boost to the US economy by 2030.
While Trump likes to say reviving coal is about jobs, it's clean energy like solar and wind where local jobs are growing at 12 times the rate of the rest the US economy.
The cost of manufacturing clean energy technology has dropped significantly, meaning clean energy is in demand and job opportunities are rife. The key now is to get governments to stop encouraging fossil fuel exploration and remove barriers to clean energy uptake.
Climate solutions have enormous benefits for families and businesses. Investing in things like home insulation, more energy efficient buildings, and better public transport reduce household costs and also make our cities better places to live.
It makes me hopeful that Mayors of 72 US cities have written an open letter to Trump saying they plan to lead action eliminating climate pollution. I'm hopeful because China, the EU, UK, and many other countries have renewed their commitment to do the same.
In New Zealand, the same opportunities exist to reduce climate pollution, improve transport and make our homes warmer, drier and more energy-efficient.
Climate solutions make sense in their own right, but they are all the more urgent while Trump remains in office.
James Shaw is co-leader of the Green Party