The United Nations warned on Monday that we have three years left to avert the worst consequences of climate change.

Human activities are releasing heat-trapping gases into the atmosphere. That has caused global temperatures to rise 1.1 degrees Celsius in the last 170 years, and the planet is on track to warm roughly 2 more degrees by the end of the century.

We have time to change our ways. Hundreds of scientists from across the globe wrote a report for the UN's Intergovernmental Panel on Climate Change.

As long as you want to keep temperatures below about 3 degrees, we need to peak emissions as soon as possible.

farmer walks through field of dried brown soybean plants
Anderson Soletti walks at his soy plantation affected by drought, in Espumoso, Rio Grande do Sul state, Brazil, on January 10, 2022.
Diego Vara/Reuters

There is a chance that the planet won't warm past 1.5 degrees if global emissions of heat-trapping gases peak by 2025. The report lays out a plan to meet the ambitious timelines.

Many of the measures in the roadmap are doable with current technology. Improved mass-transit systems offer additional benefits, like creating new jobs and addressing inequity.

The global benefits of climate action exceed the cost, according to a lead author on the report.

Byers said that it is still possible.

There are five straightforward climate actions that governments and businesses of all sizes can take right now.

Retrofit cities for electrified transit, biking, and walking

electric buses lined up inside factory
The BYD electric bus factory in Lancaster, California, on July 1, 2021.
Mike Blake/Reuters

According to the new report, cities and urban areas make up two-thirds of global emissions. Reducing urban transportation emissions by one-quarter is possible.

To make it easier for residents to commute to and from work, it's necessary to build housing near the workplace, and to design streets that encourage walking, biking, or taking public transit instead of driving personal vehicles. Public buses, trams, and other transit vehicles should be run on electricity.

The report found that the measures would save money. Local air quality would likely be improved by them.

Ditch fossil fuels for solar and wind power

wind turbines and church silhouetted against sunset
Power-generating windmill turbines beside a church in Noreuil village during sunset at a wind park near Cambrai, France, on March 18, 2022.
Pascal Rossignol/Reuters

Coal-fired power plants will not cause electric buses and trains to drive down emissions much. Fossil fuels like coal, oil, and natural gas release a lot of carbon dioxide and methane when we burn them.

The energy sector is a bigger greenhouse-gas polluter than other sectors. According to the report, 34% of all human-driven emissions were produced by energy suppliers.

Climate scientists say we must stop using fossil fuels as soon as possible.

Byers said that every pathway to limit warming to 1.5 or even 2 degrees requires the elimination of fossil-fuel use by the century's end.

worker in yellow hard hat standing amid field of solar panels spraying water
An employee works among solar panels at Bemol Solar plant outside Manaus, Amazonas state, Brazil, on August 23, 2021.
Bruno Kelly/Reuters

The good news is that solar and wind turbine costs have gone down in the last decade. Fossil fuels are more competitive with renewable energy. The report recommends that governments, businesses, and households draw energy from wind and solar farms whenever possible.

The electricity sector has made lots of progress on this, Byers said.

Cut methane emissions by patching leaks

flames black cloud rising from flarestacks natural gas facility
Excess natural gas is flared at the Cactus gas processing center, run by state oil company Pemex, near Colonia El Carmen, Chiapas, Mexico, on October 19, 2021.
Edgard Garrido/Reuters

Methane is a powerful gas with 30 times the heat-trapping potential of carbon dioxide.

fugitive emissions are leaks from fossil-fuel transportation and processing facilities. An analysis of satellite images from the last two years shows that there are more than 1,800 methane plumes all over the globe. The study calculated that the leaks were equivalent to 20 million additional vehicles on the road.

Methane has a heating effect in the atmosphere that can help reduce the speed of global warming. Energy companies would probably save money if gas leaks were patched.

That is a really low-hanging fruit that can be easily addressed.

Stop wasting food

volunteer carries bags of potatoes at drive-thru potato handout
A volunteer holds a bag of potatoes as people queue for handouts of excess potatoes at an event organized by the Washington Potato Commission in Auburn, Washington, on May 7, 2020.
David Ryder/Reuters

Garbage and cows belch methane from waste facilities. Landfills and food waste are the two largest sources of methane emissions in the US, according to the Environmental Protection Agency. 40% of the US food supply is wasted, according to the Department of Agriculture.

Reducing the amount of food eaten would mean less methane emissions at the landfill. Reducing the amount of food that goes to waste would allow us to produce less of it, which would mean less pollution from farming and food-processing machinery.

field of plowed lettuce
Acres of romaine lettuce after being plowed into the ground due to the loss of the restaurant market, in Holtville, California, on April 15, 2020.
Mike Blake/Reuters

It is a lifestyle change that can be made by individuals and families in developed countries. According to the report, household waste is the main source of food waste.

That is an easy way to both increase efficiency and reduce your own costs as a consumer, reduce the cost down the supply chain, and make a big, big difference in terms of reducing emissions, but also limiting and reducing pressure on land.

Protect forests and grow more of them

man with binoculars surveys rainforest canopy green trees
A tourist watches birds in the top of a canopy at the Manu Biosphere Reserve in Peru's southern Amazon region of Madre de Dios, on November 2, 2009.
Enrique Castro-Mendivil/Reuters

Trees absorb carbon dioxide from the air and store it in their tissues. Forests can be used to slow global warming.

The report by the Intergovernmental Panel on Climate Change calls for protecting forests across the planet from being cut down. Afforestation means planting new trees where there aren't any.

Byers said that forestation can be deployed today.

He said that it can be done in every country in the world.

The cost of the plan could be less than a ton of carbon dioxide emissions. The report estimates that half of the strategies cost less than $20 per ton. They would save money.

It isn't enough to rely on just one solution.

There are no silver bullets. We need to do it all.