Right before the new year, something unusual happened on Capitol Hill: Democrats and Republicans passed environmental legislation without any debate, and President Obama signed it into law.

You will not be surprised to learn that the issue at stake was not climate change. It was "microbeads," tiny spheres of plastic that the cosmetics industry uses in products like face wash to give people a sense of texture. The problem with microbeads is that they are too small to be filtered out of the sewage system, meaning that they were passed into the environment. As NPR reported in 2014, they increasingly ended up in the Great Lakes, where fish would confuse them for food and ingest them.

There was an environmental problem; Congress stepped in to solve it. In a time when it seems as though the two parties are at loggerheads on everything, and particularly on issues pertaining to the environment, that seems remarkable. Why was this so easy when, say, regulating greenhouse gas emissions to help combat climate change is so hard?

Rep. Frank Pallone (D-N.J.) sponsored the legislation that will ban the manufacture of products containing microbeads as of July 2017. When we spoke with him by phone this week, he offered a few reasons for why the legislation didn't prompt much dispute.

First, he noted that the chairman of the committee where the bill originated, Energy and Commerce, is chaired by Rep. Fred Upton (R-Mich.), whose district abuts Lake Michigan. For Upton and others, that proximity to the Great Lakes made the problem a local one. What's more, Pallone said, the committee "makes a real attempt to work in a bipartisan fashion." On this issue, they found consensus.

Second, the bill had the support of the industry it would regulate. "The cosmetics industry is primarily impacted by this," Pallone said, an industry that is "designed to make people look good and feel good. They would rather not have products that are perceived in a negative way from an environmental or health point of view."

Plus, the legislation made things easier for the companies. Cosmetics manufacturer Procter & Gamble, for example, was already planning to eliminate microbeads on a similar timeline. (To Pallone's point about perception, the company's statement about phasing them out notes that "there is a growing preference for us to remove this ingredient.") Pallone noted that several states were developing legislation to address the problem; for companies, it was easier to deal with one federal bill than a number of potentially different state ones.

It's easy to say how those two points contrast with the political debate over climate change. Climate change is not the sort of thing that has led to bipartisan consensus — and is also not the sort of thing that translates neatly and directly into local politics. There's clearly a gap between how much the oil and gas industries spend on lobbying Congress and backing congressional candidates ($141 million on lobbying in 2014 and $31 million on the 2014 cycle) and the amount spent by cosmetics manufacturers. But that's a function of the long-term relationship between Capitol Hill and the industry. The climate change fight is so polarized at this point that even if oil and gas companies didn't spend a dime on Congress for four years, it seems unlikely that Congress would pass significant reforms.

What's more, the coal and oil industries broadly oppose strong action directed at cutting greenhouse gas emissions because it strikes at the heart of what they do. For Procter & Gamble, products with microbeads make up only a small part of what they have to offer. For ExxonMobil, restricting products made from oil has a much bigger effect.

Pallone noted that Congress had in fact taken recent action on combating climate change. In the recently-approved federal budget, tax credits for renewable energy production were continued, which will have the effect of increasing the use of wind and solar energy. Pallone suggested that there was a trick to it. Sure, the measures tackled climate change, he acknowledged. But "as long as you don't label it as such, you have a shot at it."

And that's how you pass environmental legislation on Capitol Hill.