The Copenhagen summit will be the most important environmental conversation ever. Beginning our coverage in the run-up to the summit, Thomas Lane and the UKGBC鈥檚 John Alker look at which countries emit most carbon, and why construction will top the agenda

In three months the world will come together in Copenhagen to thrash out the most important deal yet for the future of the planet. Up to 192 nations will spend two weeks at the COP15 conference to talk about limiting carbon emissions. The final agreement, assuming one is reached, will replace the 1997 Kyoto treaty and set binding targets for developed countries.

Copenhagen is more important than Kyoto, though, because this time the US is fully engaged and China and India have now become big carbon emitters. These two countries don鈥檛 see why they should put a brake on their economies by limiting the energy available to them. This means that any deal will will hinge on what the rich nations are prepared to offer the poor in exchange for lower emissions.

What relevance does the deal have for the construction industry? In developed economies, the built environment is the principal cause of carbon emissions; it also accounts for a third of all emissions worldwide. The Intergovernmental Panel on Climate Change has warned that carbon from buildings could double by 2030. Research carried out by the UN鈥檚 environment programme suggests that emissions from buildings could be cut 30-50% without significantly increasing their cost, which means construction is the most efficient and effective lever that politician have.

If negotiations go well at Copenhagen, what effect will it have on the UK鈥檚 building legislation? Well not much: Britain already has tough, binding carbon targets, and the most ambitious carbon reduction trajectory for buildings in the world. But an agreement could provide an international market for UK expertise. Paul King, chief executive of the UK Green 黑洞社区 Council, says: 鈥淲e鈥檝e been dragged there before everyone else so we have a competitive advantage in terms of our knowledge and technology.鈥 Here we take a look at which countries are the carbon villains and which are the saints 鈥 which should give you a good idea of where the carbon reduction markets are.

A call to action

The UK Green 黑洞社区 Council (UKGBC) will launch a call to action on World Green 黑洞社区 Day. This is one of many events around the world on 23 September and aims to put buildings high on the agenda at Copenhagen. The UKGBC event is hosted by Emily Thornberry MP and David Kidney MP, who is the undersecretary of state for energy and climate change. They will listen and respond to the call for action. If you would like to attend or would like more information on the call for action go to www.ukgbc.org/international. There is a charge of 拢85 (拢60 for UKGC members).

Who鈥檚 responsible?

UK

The built environment鈥檚 contribution to carbon emissions
42% (15% public and commercial buildings, 27% homes)

Is that likely to change?
An ageing population and an increase in single-person households will require more building.

Are buildings green exemplars or gas guzzlers?
Britain has always built guzzlers: energy regulation is a recent development. Although things have improved since 2002, carbon reduction will have to focus on the existing stock.

What they say about reducing emissions?
Probably the most ambitious targets set of any major emitter. An 80% cut is required by 2050 and a 30% cut by 2020, which could rise to 40% after Copenhagen.

What they are doing about it?
The UK鈥檚 energy reduction plans for new buildings lead the world. All houses are to be zero carbon by 2016 and all other buildings by 2019. The record is not so good when it comes the existing stock, although a recent heat and energy saving strategy raised the potential for stronger policies.

Australia

The built environment鈥檚 contribution to carbon emissions
Residential and commercial buildings contribute 35% of greenhouse gases. Grid electricity has a high carbon content of 1kgCO2/kWh thanks to coal power, which means buildings play a critical role in reducing emissions.

Is that likely to change?
No, because of the country鈥檚 stable population and economic growth rates.

Are buildings green exemplars or gas guzzlers?
Eleven per cent of Australia鈥檚 city centre office buildings have Green Star certification (this is Australia鈥檚 own environmental standard).

What they say about reducing emissions?
The targets are a 5-15% reduction by 2020 (based on 2000 levels) and a 60% reduction by 2050.

What they are doing about it?
The government requires minimum standards for buildings it occupies, as do most state governments. In several, this also applies to schools and hospitals. Councils are beginning to require Green Star certification as a condition of planning.

Brazil

The built environment鈥檚 contribution to carbon emissions
42%, of which 23% is residential, 11% is commercial and 8% is public.

Is that likely to change?
Yes, Brazil expects to double energy use by 2030.

Are buildings green exemplars or gas guzzlers?
Brazil is a mixture of modern industrial cities and shanty towns and is not known for green construction.

What they say about reducing emissions?
Brazil has said it will not limit its emissions until the middle of the century. However President Lula da Silva recently said Brazil could adopt targets if rich countries did more.

What they are doing about it?
Climate change policy in Brazil is dominated by deforestation and biofuels. However, policy is developing. Federal law requires new buildings to improve energy efficiency and municipal laws require that builders prove the implementation of waste treatment in their projects. In addition, solar energy panels are receiving a lot of incentives and undergoing rapid expansion.

China

The built environment鈥檚 contribution to carbon emissions
42%

Is that likely to change?
China is expected to add twice the amount of current US office space between 2000 and 2020. Carbon emissions could double by 2030.

Are buildings green exemplars or gas guzzlers?
By 2015 half of all the buildings in China will be less than 15 years old and will use four times as much energy as European ones.

What they say about reducing emissions?
In the five-year plan that ends next year, China says it will cut carbon emissions 10%. China has set a target of doubling renewable energy generation to 15% by 2020.

What they are doing about it?
The five-year plan sets out to halve the energy used by buildings. The longer-term aim is to cut emissions 65% by 2020. There are building codes intended to help achieve more efficient buildings, issued in 1986. However, by the end of 2000 only 5% of new buildings actually met these standards.

Germany

The built environment鈥檚 contribution to carbon emissions
35%

Is that likely to change?
Probably not greatly.

Are buildings green exemplars or gas guzzlers?
Germany鈥檚 approach to green construction is seen as exemplary. It is the home of the Passivhaus and has been implementing energy-saving policies since the seventies. It is also the home of low-energy cities such as Freiburg, and has already upgraded the energy efficiency of half of its existing housing stock.

What they say about reducing emissions?
Germany has committed itself to reducing its carbon emissions 40% by 2020. It hit its Kyoto target of reducing 1990 emissions by 20% with five years to spare.

What they are doing about it?
Germany鈥檚 energy regs are being updated for 2009 and require 15% of heating and cooling energy to be provided from renewables. Low interest loans were available for renovations from the state-owned Kreditanstalt f眉r Wiederaufbau bank.

India

The built environment鈥檚 contribution to carbon emissions
30%

Is that likely to change?
Yes. India鈥檚 economic growth is second only to China so carbon emissions could quadruple by 2030. Like China, the government does not see cutting emissions as a priority, as almost half of India鈥檚 population has no access to the electricity grid, and many more people suffer regular power cuts. In the world鈥檚 largest democracy, improving this situation is a regular election promise.

Are buildings green exemplars or gas guzzlers?
Many Indian people live in basic shacks, so energy use is minimal. However, the picture is different in cities, where building standards are poor and many are air-conditioned.

What they say about reducing emissions?
Not a lot. India has only committed itself to not exceeding the per capita emissions of the developed world and has said it will resist legally binding caps at Copenhagen.

What they are doing about it?
Very little.

South Africa

The built environment鈥檚 contribution to carbon emissions
23%

Is that likely to change?
South Africa plans to build 14 million homes in the former black townships.

Are buildings green exemplars or gas guzzlers?
South Africa has some of the world鈥檚 cheapest electricity generated largely from coal. This has resulted in a great deal of energy-inefficient design.

What they say about it?
The South African government has been relatively active in publicly recognising the problem of climate change and in setting tough targets for mitigation. The country expects to put in place a binding climate change policy within three years to cap emissions between 2020 and 2025.

What they are doing about it?
South Africa plans to generate 15% of its electricity from renewable sources by 2020 and the government鈥檚 draft energy efficiency strategy includes a target of 20% energy demand reduction by 2014. However, it is debatable whether implementation is keeping pace
with policy.

UAE

The built environment鈥檚 contribution to carbon emissions
Data unavailable, but likely to be more than 40%

Is that likely to change?
Yes, despite the downturn, expansion is the name of the game. Abu Dhabi wants a growth rate of 7% between now and 2015.

Are buildings green exemplars or gas guzzlers?
Most buildings in the region are gas guzzlers; hotels use double the energy of ones in Europe. Energy is very cheap and until recently there has been no regulation of its use in buildings. Glass is a popular cladding material and many buildings are very inefficient.

What they say about reducing emissions?
Abu Dhabi has set a target of producing 7% of its energy from renewable sources by 2020.

What they are doing about it?
Despite the feeble targets, Abu Dhabi is serious about reducing emissions. The $15bn (拢9bn) Masdar Initiative is investing in a range of carbon-cutting technologies and work has started on the Masdar City zero-carbon scheme.

US

The built environment鈥檚 contribution to carbon emissions
40%

Is that likely to change?
Emissions are slowly rising with the population but the main challenge will be decarbonising the existing stock. Industrial emissions are likely to fall in step with US鈥 manufacturing base.

Are buildings green exemplars or gas guzzlers?
They are guzzlers: 86% of homes have air-conditioning.

What they say about reducing emissions?
Barack Obama鈥檚 climate change bill, passed in July, sets the target of a 15% cut in current emissions by 2020 and 80% by 2050.

What they are doing about it?
The government is reducing the use of fossil-fuel energy by 55% by next year in new and refurbished federal buildings, and by 100% by 2050. By 2030 all new commercial buildings have to be zero energy and 50% of existing offices must follow suit by 2040 and 100% by 2050. Individual states are going much further.