In the annals of America's political response to the looming threat of climate change, few moments will resonate over the long term more than what happened on the Senate floor in February 2015.

Sen. James M. Inhofe (R-Okla.) strode into the chamber with a prop: a snowball.

On Feb. 26, 2015, Sen. James Inhofe (R-OK) brought a snowball to the Senate floor. (C-SPAN)

“In case we had forgotten, because we keep hearing that 2014 was the warmest year on record, I ask the chair, do you know what this is? It's a snowball, just from outside here,” Inhofe said. “It's very, very cold out. Very unseasonable.”

It was cold out, so one should treat this “warmest year” thing with skepticism. And because you should treat that warming record with skepticism, you should also treat the idea of global warming with skepticism. So argued the author of “The Greatest Hoax” — a book whose title referred to the concept of climate change itself.

Of course, it wasn't unseasonably cold the day Inhofe found his snowball, it was seasonably cold. It was February, a month during which one would expect to find snow, even in a warmer climate. That February was about average as far as Februarys go in the United States; the Northeast was particularly snowy. Global warming doesn't mean no snow immediately, any more than evolution means monkeys will spontaneously become humans. But just as those who deny evolution might point to the existence of apes as a rebuttal to the scientific consensus, Inhofe tossed his snowball.

As it turned out, 2015, like 2014, ended up setting a global record for warmth. Relative to the average temperatures recorded during the 20th century, no year had been warmer than 2014 until 2015. Snow in Washington notwithstanding, global temperatures were peaking.

2015's warmest-year record has now also been broken, according to the National Oceanic and Atmospheric Administration. The new hottest year on record is 2016, during which time surface temperatures globally were 0.07 degrees Fahrenheit warmer than 2015. “We don't expect record years every year, but the ongoing long-term warming trend is clear,” Gavin Schmidt of the Goddard Institute for Space Studies said, according to The Washington Post's Chris Mooney.

In the United States, 2016 was the second-warmest year on record, trailing only 2012. It was also the year that we elected Donald Trump to serve as president.

It's likely that Trump's inauguration will take place on one of the warmest Jan. 20s in Washington's recorded history. The existing record is 70 degrees, in 1951. Most likely, temperatures will be in the 50s for Trump's big day. If the temperature went much higher, it'd be safe to declare it “unseasonably warm.”

But this is the trap we get into when we talk about climate change, the trap exploited by Inhofe and others who deny the scientific consensus on climate change.

Over time, presidential inaugurations haven't gotten much warmer.

(The Washington Post)

The warming trend doesn't really manifest that neatly. Climate change is about long-term patterns and shifts that allow us to make broad predictions about what we might see. 2017 could be colder than 2016 by some large extent, but that wouldn't undercut the long-term warming trend seen in the graph above. On any given Jan. 20 in Washington, temperatures could be colder or warmer than normal — they won't necessarily always be warmer. And in February, we can still expect to see the occasional snowfall. A cold day doesn't disprove climate change any more than a warm one proves it.

On Twitter, Trump has used the Inhofe but-it's-cold-in-winter argument to try to undercut climate science. Here he is, at about the time Inhofe was packing his snowball.

As president, Trump will have a great deal of power over the extent to which the United States will work to combat climate change. Every indication is that he will not demand quick action.

On Wednesday — the day the 2016 record was announced — Trump's nominee to run the Environmental Protection Agency was on Capitol Hill for confirmation hearings. The EPA plays a critical role in the fight against climate change. During the administration of President Obama, it leveraged that power to regulate carbon dioxide emissions as a pollutant (determined in a Supreme Court case in 2007) and to create new rules limiting that abundant greenhouse gas. (Scientists believe that atmospheric warming occurs because gas in the atmosphere traps heat, preventing it from escaping into space.) Trump's nominee Scott Pruitt, as attorney general of oil-producing Oklahoma, fought the EPA's Clean Power Plan, which aims to reduce emissions from coal-burning power plants.

During the Wednesday committee hearing, Pruitt said that climate change wasn't a hoax (contrary to past comments from Trump) but that the connection between human activity (like burning coal and oil) and warming is “far from settled.” Introducing Pruitt to the committee? His state's senior senator: James M. Inhofe.

Again, it's not just that 2016 was the warmest year on record that should inspire Trump and Pruitt to want to take action to curtail warming. It's things like how global sea ice is at its lowest level on record. One of the most immediate threats from climate change is rising sea levels, which is a function both of huge volumes of melting ice and warmer ocean temperatures. (Warmer water takes up more volume, so sea levels rise.) Those higher sea levels are already threatening coastal communities, including in Florida. Trump's resort at Mar-a-Lago — which he dubbed the Winter White House on Twitter — is threatened by the rising ocean.

There are other likely long-term effects, too. Longer, more severe droughts. Higher-intensity precipitation events. Thawing permafrost, destabilizing established communities and potentially releasing the greenhouse gas methane as previously frozen vegetation begins to rot. Is climate change behind California's recent drought, or the record flooding in the South in recent years? Scientists can't say definitively, just that these are the sorts of things we'd expect to see more of.

The inability to point directly at the effects of climate change has fueled much of the Pruittian “the science isn't clear” argumentation, which itself has fueled a deep partisan split on the urgency of addressing climate change before global temperatures increase further. In Oklahoma, there's an economic rationale not to want to address climate change: Scientists say they believe the oil that powers the state's economy helps contribute to the problem. Moving away from oil would mean moving away from spending on a key part of the state's economy.

Scientists also say they believe that avoiding the worst effects of climate change means holding warming to 2 degrees Celsius above preindustrial temperatures. To avoid passing that mark, the world needs to quickly cut back on its use of fossil fuels. They believe, in other words, that this is a moment to move more quickly on climate change, not move in the other direction.

In 2015, the Obama administration signed a global agreement in France to reduce emissions. By looping in other major greenhouse gas emitters, the agreement addressed one of the purported concerns of those nervous about climate change: The United States would be at an economic disadvantage if we couldn't use cheaper fossil fuels but, say, China could. The Paris agreement would demand cuts over the long term from our competitors as well.

Inhofe released a statement bashing it. On the campaign trail, Trump indicated that he would back out of the agreement. The United States, during the so-far-hottest-year in recorded history, decided through its electoral college votes to sideline efforts scientists believe will keep the problem from becoming a catastrophe.