COPENHAGEN, Denmark -- This city plans to invest in wind farms, electric cars, bike paths and energy-efficient buildings in an effort to become the world's first carbon-neutral capital by 2025.

The Danish capital, its inhabitants and its businesses will spend as much as $4.7 billion in the next 13 years to reach this goal, city officials explained as they rolled out their climate plan.

"Copenhageners' daily lives will become better in a greener and healthier city," said Frank Jensen, the city's mayor. "The investments will ensure jobs now, and the new solutions will provide the foundation for a strong green sector."

Extensive retrofitting of buildings, more wind turbines and changing transport habits will lead to a reduction in carbon dioxide emissions of around 1.2 million tons per year while creating economic growth and improving quality of life, city planners said.

"The goal is realistic and economically viable, but it also needs support and investment from the citizens of Copenhagen and the private sector," said Rikke Houkjær, a spokeswoman for the city.

The plan will require municipal investment of around 2.7 billion Danish crowns, or $450 million, up to 2025. In addition, new private investment of 20 billion to 25 billion crowns will be needed, resulting in employment of about 35,000 man-years until 2025, according to the city. Once the plan's goals are achieved, city dwellers will save 350 crowns per month on their power and heating bills, the municipality estimates.

The plan is scheduled to be discussed and approved in several city committees starting this week before final approval in the City Council on Aug. 23.

The council unanimously decided in 2009 that the city would cut its CO2 emissions by 20 percent by 2015 compared with 2005 levels and become carbon neutral in 2025. Current statistics show the city would meet its 2015 goal, and Copenhagen for the first time presented its plan for how to move forward to the 2025 target.

Building on existing policies

Copenhagen emitted 1.9 million tons of CO2 last year. Even without any new initiatives, this is projected to fall to 1.16 million tons by 2025 because of steps already set in place, such as tighter E.U. emissions standards for cars, an increase in production of renewable energy and replacement of some coal power plants with ones that burn biomass.

Energy efficiency will account for 7 percent of the CO2 reductions needed to get from 1.16 million tons to net zero in 2025, the city said. Renovation of existing buildings and stricter efficiency requirements for new buildings will lead to a 20 percent reduction in heating demand, 20 percent reduction in commercial electricity consumption and 10 percent reduction in residential electricity consumption.

In addition, roof-mounted solar panels, now virtually nonexistent in the city, will produce 1 percent of electricity used locally.

An additional 74 percent of the reduction will come from more use of onshore and offshore wind power, a new biomass power plant, a new geothermal plant, and better sorting of plastic trash so that it doesn't end up in the garbage that's being burned in plants that produce district heating.

More bike paths, the introduction of hybrid and biogas buses, and wider use of electric cars will contribute an additional 11 percent of the reduction, according to the plan. By 2025, 75 percent of all city transportation will take place on foot, by bike or by public transit. Fifty percent of commuting to work will happen by bike, up from 33 percent now. Public transit will have 20 percent more passengers and will be by itself CO2 neutral.

"We will only achieve a carbon-neutral capital with the support and commitment of Copenhageners," said Ayfer Baykal, who heads technical and environmental affairs at Copenhagen City Hall. "We must choose our bikes instead of our cars, sort and recycle more of our waste, and invest in retrofitting our houses and flats. The reward will be clean air, less noise and better quality of life."

'Cycle superhighways' from the suburbs

To encourage even longer commutes to work by bike, Copenhagen opened the first of 26 "cycle superhighways" this year. A 22-kilometer (13.7-mile) bike lane with stoplights synchronized to favor cyclists was opened at a cost of 14.2 million crowns to connect downtown Copenhagen with the suburban town of Albertslund. Two more routes will open later this year.

Copenhagen is big enough that its climate solutions are relevant in an international setting but small enough that it can try out new ideas. The inner city of 537,000 is projected to grow by 100,000 inhabitants by 2025 and will have 20,000 more jobs, which will require 6.8 million square meters of new commercial and residential real estate.

The city will invest 1.4 billion crowns to renovate buildings owned by the municipality as well as replace streetlights with more energy-efficient bulbs. It aims to cut energy use in its own buildings by 40 percent and on-street lighting by 50 percent. All city vehicles will run on electricity, hydrogen or biofuels by 2025.

The city hopes its green plan -- which covers the Copenhagen municipality only, not the greater Copenhagen area of 1.5 million people with suburbs -- will also make it a knowledge hub, with an ambition to attract and keep scientists and high-tech companies from elsewhere.

Since 1990, Copenhagen has reduced its CO2 output by 40 percent while its economy has grown by 50 percent. A large part of the reduction was due to the fact that 98 percent of the city uses district heating. When heat and electricity are produced simultaneously, energy is used almost twice as efficiently while cutting city inhabitants' heating bills.

The green economy employed 11,000 people in Copenhagen in 2009 and had revenues of 24 billion crowns, out of which 10.5 billion crowns was exports, according to the city. The city's economy grew 3 percent in 2010, more than double Denmark's 1.3 percent GDP growth that year.

Becoming carbon-neutral doesn't mean there will not be any CO2 emissions in Copenhagen in 2025. The city acknowledged that at least some private traffic will most likely continue to run on fossil fuels. It plans to compensate for that by being a net "exporter" of renewable energy to other areas in Denmark's energy system, where it would replace coal.

But because Denmark plans to be totally independent of fossil fuels by 2035, this calculation will no longer be valid at that time, so Copenhagen will have to continue efforts to reduce its CO2 output in the 10 years after 2025, city planners acknowledged.

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500