Carbon is at the center of most environmental problems. Reducing food waste, consciously choosing low emission transportation and adopting new business practices are key ways Americans can trim carbon emissions and work towards greater environmental sustainability by 2020.

Eliminate Food Waste

A striking forty percent of food is thrown away. Most of it ends up in landfills, where it produces powerful methane gas as it rots, or is tossed into incinerators. According to a United Nations report, “If food wastage were a country, it would be the third largest [carbon] emitting country in the world.” (China and the United States take first and second place, respectively.)
So eat your leftovers! There are numerous apps to help you keep track of the food in your refrigerator. FoodKeeper provides guidelines for how long food is safe to eat.  (You can eat leftover rotisserie chicken for up to four days, if you’ve kept it refrigerated.) And Foodfully (which is currently in beta) eliminates food waste by keeping you from buying an extra head of lettuce you might not need because you’ve forgotten you already have one.
Beyond your own home, get involved with the Food Recovery Network, Food Cowboy, Zero Percent, and Spoiler Alert, which all redirect food, from restaurants, schools and food manufactures to people who need it.
“There are things we can do as individuals to clean our plate,” says Jeremy Kranowitz, executive director of Sustainable America. “Some municipalities, Seattle and San Francisco; states like Vermont and Connecticut (to a lesser extent) and counties like Westchester in New York are starting to ban food waste from their landfills.”  

Choose Low Emission Transportation

Strict fuel economy standards have been rolled back, but that doesn’t mean more vehicles are suddenly going to spew carbon-laden smog into our skies. Many people’s daily routines now depend on carpooling, walking or biking, and public transportation. According to a CDC study, kids that walk or bike to school (instead of being dropped off in the family car) are preventing hundreds of thousands of tons of carbon from being emitted into the atmosphere. Rather than buying a new car, you might consider a new pair of sneakers or a bike lock.
If that’s not practical, keep your eye on the prices of electric cars compared to traditional gas guzzlers. In January 2017, Ford CEO Mark Fields announced, “The era of the electric vehicle is dawning” and that the company planned to release 13 electric cars in the next five years. Meanwhile, Bloomberg New Energy Finance predicts that electric cars will be as affordable as regular cars by 2022.   
“While the economics of EVs are becoming attractive to consumers, their ‘high-tech’ nature will also be an important factor in future purchase decisions,” says Jack Gillis, director of public affairs at the Consumer Federation of America.
The promise of an electric future has prompted 30 cities, including Chicago, Los Angeles and New York City, to jointly inquire about the purchase of more than 100,000 zero-emissions vehicles for police, fire and sanitation department usage. As a taxpayer and a voter, you have the ability to support these local initiatives.

Make Sustainability a Workplace Priority

At work, employees are increasingly looking for better sustainability practices. According to the 2017 Deloitte Millennial Survey, only 13% of millennials believe their companies are addressing the issue of climate change, while a majority of these younger workers are concerned about our environment.  
So, if you’re a mid-level manager or a hiring team, take action.  Create incentives for so-called “green” programs in your office and use them as recruiting tools.  You might take inspiration from the new trend of linking executive pay to energy consumption and carbon emission targets. For example, Royal Dutch Shell recently announced that a portion of its executives’ bonuses will be based upon meeting operational greenhouse gas emission goals.  
“Linking performance management with sustainability efforts places societal impact at the forefront of the company ethos and generates fuller employee buy-in,” says Nathaniel Wong, a manager of social impact strategy at Monitor Deloitte, adding, “these incentive structures may also foster internal [sustainability] innovation.”
And according to this Harvard study, workplace incentives may not need to be monetary to be effective in driving carbon emission reductions.
Behind the Quiet State-by-State Fight Over Electric Vehicles, The New York Times
The Low Carbon Economy, Goldman Sachs