As cities pledge to plant more trees, ban diesel vehicles and make the switch to renewable energy, it's becoming increasingly clear that urban areas — home to more than half of world's 7.5 billion people — will be central in efforts to tackle the climate crisis.

That's the message of a new report released by the Coalition for Urban Transitions (CUT) on Thursday. In the climate fight, "the battle for our planet will be won or lost in cities," it says.

With urban areas responsible for around three-quarters of the world's total carbon emissions, it says a major shift in how cities handle their CO2 — or don't — could significantly influence global efforts to reach net-zero carbon emissions by 2050 and limit global warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) by the end of the century.

Read more: German environment minister: No more 'soapbox speeches' on climate protection

The report, compiled by more than 50 organizations including the World Resources Institute and the C40 Cities network and funded in part by the German Environment Ministry, points out that climate-friendly economic and social development plans will not only help reduce emissions but also "enhance economic prosperity [and] make cities better places to live."

"This demonstrates that it is wholly feasible, using proven technologies and practices, to cut emissions from urban areas by 90% by 2050, just with the technologies and practices that we already have in place," said Sarah Colenbrander, lead author of the report.

Those cuts would deliver more than half of the world's needed carbon reductions, and at the same time create "places where people are healthier and more productive."

Here's a look at some of the recommendations about what cities could do:

Finance sustainable urban initiatives and infrastructure (some examples: eliminating fossil fuel subsidies and supporting alternatives to car travel, and backing a robust and effective carbon price scheme that would serve as an example for the private sector).

Develop strategies to promote low-carbon, climate resilient economic and social growth for all citizens (by supporting low-carbon industries and developing transition plans for fossil fuel-based workers and industries).

Coordinate and support urban climate action and policies (by passing legislation to allow cities to become more dense and limit urban sprawl, decarbonize their energy grids and find greener construction alternatives to steel and concrete).

Over three decades, Medellin went from the "world's deadliest city" to a zone of innovative public transport solutions

Where this is already happening

The CUT report gives numerous examples of cities and regions that have already been transformed by focusing on low-carbon, participatory development and efforts to eradicate poverty and reduce inequality.

Nearly 30 years after ranking as the "world's deadliest city," Medellin — the former poverty-stricken center of Colombia's drug trade — now boasts higher living standards thanks to solid municipal development plans for neglected neighborhoods and public transport upgrades. Cable cars that connect poorer areas of the city have ushered in an era of innovative public transport solutions for a network that now accommodates 256 million passengers a year.

Read more: To combat climate change, increase women's participation

Residents of the megacity of Indore went from suffering from noxious smog and human waste in the streets in 2016 to living in India's cleanest city by 2018. The dramatic makeover was thanks to ambitious waste management projects funded by public and private partners and legislation changes at the national level.

And in Germany, the transition to renewable energy over the last two decades — from 6% of electricity production in 2000 to 38% in 2018, resulting in hundreds of thousands of new jobs — has been achieved through a combination of national policies, partnerships between federal and city governments and citizen-owned energy initiatives.

Cities in climate crisis Paris: Sweltering microclimate France hit record temperatures this summer, and the urban heat island effect means cities are particularly hot. While vegetation releases water into the atmosphere, cooling things down, concrete and asphalt trap heat. During a heat wave, Paris can be 10 degrees hotter than the surrounding countryside. Pollution also builds up in slow-moving summer air — another reason urban heat waves can kill.

Cities in climate crisis New Orleans: In the eye of the storm In August 2005, Hurricane Katrina tore apart one of America's most iconic cultural heartlands. Even though it's rebuilt, New Orleans has been battered again and again by powerful storms. A government report last year said the US southeast was "exceptionally vulnerable to sea-level rise, extreme heat events, hurricanes and decreased water availability." Trump's response? "I don’t believe it."

Cities in climate crisis Chennai: No more water This year India's monsoon was the second driest in 65 years, leaving 44% of the country suffering from drought. In Chennai, things have become desperate: its main reservoir has dried up, residents are queuing for hours at pumps, water is being trucked in and hospitals are under pressure. As the planet heats up, more and more cities could run out of water.

Cities in climate crisis Siberia: Cities on thin ice Arctic temperatures are rising faster than anywhere else on Earth. This is taking its toll on cities in Russia's far north, as the permafrost beneath building foundations begins to melt. Cities like Norilsk and Yakutsk are already seeing serious subsidence, and scientists expect their infrastructure to become at least 25% less stable by mid-century.

Cities in climate crisis Jakarta: Sinking into the sea Rising seas threaten coastal cities the world over, but Jakarta, with 13 rivers, suffers more floods than most. Limited access to water means residents pump it from underground aquifers, causing subsidence. By 2050, 95% of North Jakarta could be submerged. Indonesia is building the world's biggest seawall to protect its capital, but that could leave thousands of fishermen without homes or income.

Cities in climate crisis Dhaka: Climate refugees Some 28% of the population of Bangladesh lives on the coast, and high tides are rising 10 times faster than the global average. In 2018, natural disasters displaced 78,000 people, with riverbank erosion — expected to increase as Himalayan ice melts — moving many more. Already one of the world's most densely populated cities, the capital of Dhaka takes in 1,000 new migrants every day. Author: Ruby Russell



Time is of the essence

But cities can't afford to waste any time enacting these changes, with the CUT report warning of a "short window of opportunity." Any urban plans launched today — infrastructure, transport, energy supplies, buildings — will likely still be in place decades from now.

Listen to audio 03:53 Share Living Planet: Can reflective roads help LA keep its cool? Send Facebook google+ Whatsapp Tumblr linkedin stumble Digg reddit Newsvine Permalink https://p.dw.com/p/2x6Jy Can reflective roads help LA keep its cool?

"The policies and investments made in the next two decades will determine the quality of life on this planet for generations to come," said British economist Nicholas Stern of the London School of Economics, in the report.

Speaking to the press, Christiana Figueres, a former UN climate official and current vice chair of the Global Covenant of Mayors, a coalition of more than 10,000 city leaders addressing climate change, stressed the importance of national support for these plans.

"Cities cannot do this alone," she said. "All of these mayors have pledged and are working toward decarbonizing their urban areas, but there is a very clear limit as to what they can do without a coherent policy with national governments."

The report's authors noted that even if support for climate policies falls short at the national level, commitment at the local level can still make a big difference.

"Cities aren't waiting for anybody to take action," said Eric Garcetti, mayor of Los Angeles, pointing out that cities can enact many necessary measures on their own. In the US, "where the Trump administration is actively pulling us backward in the fight against climate change, mayors and cities are still doing the work that serves our residents and our futures."

Watch video 04:42 Share Athens battles the drought Send Facebook google+ Whatsapp Tumblr linkedin stumble Digg reddit Newsvine Permalink https://p.dw.com/p/3OYxj Athens battles climate change

Other challenges

Commenting ahead of the report's publication, Felix Creutzig of TU Berlin's Institute of Landscape Architecture and Environmental Planning also pointed to the difficulty of convincing fast-growing urban centers in developing countries like China, India and much of Africa that they should give up the easy, fossil-fueled path to development enjoyed by wealthier nations in North America and Europe.

"Importantly, the 'American way of life' still serves as a role model in many countries," Creutzig told DW in an email. "There is a need to build visuals and imagery that depict a status-rich low-carbon way of life that is inclusive and just."

Read more: Greta Thunberg: The teenage eco-activist who took the world by storm

Looking ahead to UN climate smmit

One of the main issues up for discussion at next week's UN Climate Action Summit in New York will be how the world can bring about a "full transformation of economies in line with sustainable development goals." In its report, CUT says cities are in a prime position to contribute to this shift.

"[The UN summit] is the time for national governments to demonstrate leadership and seize the urban opportunity," says the report. With countries boosting their efforts to reduce emissions ahead of the COP26 climate change conference in late 2020, "it is vital that cities are at the heart of their low carbon economic and development priorities."

CUT warns that the next 15 months will be "critical in tackling the climate crisis," with world leaders aiming to intensify their 2020 climate goals in an effort to reduce greenhouse gas emissions by 45% over the next decade.

Watch video 02:41 Share Growth of urban farming systems in Nigeria Send Facebook google+ Whatsapp Tumblr linkedin stumble Digg reddit Newsvine Permalink https://p.dw.com/p/3BKtD Growth of urban farming in Nigeria

Every day, DW's editors send out a selection of the day's hard news and quality feature journalism. Sign up for the newsletter here.