A particular challenge of the fight over climate change, if not a unique one, is that the shifts accrue subtly. The climate has changed stunningly quickly in global terms but slowly in human terms, allowing us to rationalize, wave away and downplay.

It’s that slowness, the ability to adjust to slight changes, that has led to the political fight over how to address climate change. The effects of the warming planet are only intermittently tangible, and there are still winters, and there’s a robust vested interest by major corporations that sell coal and natural gas and oil in continuing to sell coal and natural gas and oil.

The issue of climate change rose to the national consciousness as polarization in U.S. politics spiked. That national attention was spurred in part by Al Gore’s 2006 film “An Inconvenient Truth,” meaning that Gore and his politics became part of the association many Americans made with the issue. Climate change is now one of the most politically polarizing issues in the country. Gallup polling shows that there’s a nearly 50-point gap between the parties in belief in the effects of a warming planet having already begun. More than 8 in 10 Democrats think global warming has been demonstrated; only a third of Republicans agree.

Nearly all scientists who study the issue agree with the Democratic and independent majorities, but scientists haven’t convinced Washington.

In fact, to the extent that action on addressing climate change is still a viable fight in the capital, on Tuesday we could declare a winner: Climate change is here, and the United States has accepted it. President Trump’s decision to roll back even measured efforts to curtail carbon-dioxide emissions and news about Arctic sea ice combine to paint a picture of leadership that’s living through climate change and deciding, for the indefinite future, not to do anything about it.

It has been a ferocious summer for global weather. The Washington Post’s health and science team outlined extremes seen in the Northern Hemisphere last month: spiking temperatures, rampant wildfires, deadly heat waves.

That map excludes other significant incidents, such as California’s suffering several of the largest wildfires in its recorded history over the past month.

One of the more effective refrains of those skeptical of addressing climate change is that weather and climate are not the same, an argument that’s effective because it’s true. Pointing to specific weather incidents as proof of climate change is like pointing to a fever and chills as proof of the flu: Maybe there’s some other cause. But these are certainly symptoms of what we expect from a warming world: more temperature extremes; more severe droughts; more extreme precipitation events, as in Japan last month or Houston last year.

Those extremes are happening alongside longer-term trends that also reinforce how the climate is warming. On Monday, The Post reported on the pocketbook effects of rising sea levels, with residents of Charleston, S.C., facing repeated flooding incidents. Southern Florida now floods so much that it barely makes the news, a function of the slow transition from higher sea levels being exceptional to their being the norm.

A new study also reveals that some areas in the Arctic are no longer freezing, suggesting that areas that have been frozen for centuries are at risk of thawing. When they do so, plant material that has been frozen could begin to decompose, releasing methane into the atmosphere. Methane is much better at trapping heat than carbon dioxide.

Elsewhere in the Arctic, the annual minimum in sea ice coverage has been steadily dropping, meaning that less and less of the Arctic Ocean is covered by ice. This year is well below the norm in terms of August coverage.

But then came a new report Tuesday with worse news: For the first time on record, the thickest Arctic sea ice began to break apart this year.

“The thinning is reaching even the coldest part of the Arctic with the thickest ice,” Walt Meier, a senior research scientist at the National Snow and Ice Data Center told the Guardian. “So it’s a pretty dramatic indication of the transformation of the Arctic sea ice and Arctic climate.”

A long-term trend that has a sudden new indication of its severity.

Those opposed to taking action on climate change, though, will often point to the existence of sea ice as evidence that climate change as a problem is overblown. Gore’s frequent assertions that the Arctic could be ice-free by 2014 (though it could perhaps take longer) are cited as evidence that his claims about the changing climate were suspect. Politics and climate change are intermingled. Even Mitt Romney, during his 2012 bid for the presidency, was prompted to take a shot at Barack Obama’s climate-change advocacy despite Romney, like many Republican officials, embracing the need to address climate change during the spike in public interest a decade ago.

Trump made rejecting the need to address climate change central to his candidacy for the White House. Sure, he once signed an open letter calling on Congress and Obama to address climate change, but he renounced that position in short order. Before he announced his candidacy, his Twitter feed was littered with tweets of skepticism about global warming; afterward, he made an embrace of the fossil-fuel industry central to his pitch to voters.

On Tuesday, the administration announced a long-expected move: The Environmental Protection Agency was replacing Obama’s plan to limit pollution from coal-burning power plants with a plan of its own, which would allow more pollutants to escape into the atmosphere. That includes greenhouse gases such as carbon dioxide, which get trapped in the atmosphere and keep heat from escaping into space. It also includes particulate matter, microscopic particles that can be inhaled and lead to health complications. As the New York Times notes, the EPA’s announcement itself estimates that 1,400 more Americans may die annually because of the increased number of particulates allowed to be emitted from power plants.

At its heart, though, this is a decision about whether to make the decisions necessary to try to limit the long-term effects of climate change. Again, there’s little question in the scientific community that the climate is changing as a result of human activity, something that most Americans accept. The question is whether the country and planet decide to make the changes needed to reduce how severe the changes to the climate will get. Trump, true to his campaign promises, said no in the abstract last year when he pulled out of the global Paris climate accord. The decision on power plants, though, is more significant because it’s more concrete. Power-plant emissions are one of the largest sources of greenhouse gas emissions in the United States, and the Trump administration has decided to set aside a significant effort to curtail them.

That’s coupled with the administration’s decision this month to freeze fuel-efficiency standards for vehicles rather than allow mandated improvements to those standards to move forward. Vehicular emissions are the other biggest source of greenhouse gas in the United States.

It’s just coincidence that the Trump plan on power plant emissions should be announced the same day as the news about Arctic ice is reported. Any number of other things could have combined in a similar way to make obvious the split between what’s happening in the world and what’s happening in Washington. Both of the developments Tuesday, though, are very significant and very telling. For those eager to have bolder action from political leaders on slowing changes to the climate over the long term, a key frustration is how humans perceive time itself.

The capital is a place where political effects are measured in the scale of days, if not minutes. The global climate shift is measured in years, if not decades. And, slowly, this is the point we’ve gotten to.

The headline of this article has been changed to reflect that, in keeping with the theme of the article, the effort to address climate change is a slow, ongoing process.