A green audit has given a mixed report into how sustainable the Welsh Assembly Government is in its operations.
The Sustainable Development Commission (SDC) found a 2% rise in emissions from road vehicles used on government business despite a target to cut them.
But the assembly government had cut waste and most its power supply was from renewable sources.
Minister Jane Davidson said the assembly government had made progress and would "address any shortcomings".
The SDC's first annual sustainable development in government (SDIG) report on the assembly government estate covers the 2008-9 period, and makes for mixed reading.
The report said the assembly government made good progress on waste - having cut waste arising by 5.4% over the year, meeting its 2010 target early.
It found that 85% of electricity supply contracts were now 'green tariff' - from renewable energy sources - providing 73% of electricity consumed in all offices.
However carbon emissions from road vehicles used for assembly government business travel went up by 2%, despite a target to cut these emissions.
Carbon dioxide emissions fell by 4% year-on-year, but the commission said the fall represents insufficient progress if the assembly government is to meet its 2010 target.
Water consumption was increasing, the report showed.
Peter Davies, commissioner for Wales at the SDC, said: "There are clear signs that the Welsh Assembly Government is starting to tackle the sustainability of its own estate, with good progress on waste and sourcing electricity from 'green' tariffs.
"However, the report also highlights areas which need a marked improvement, such as water consumption and transport emissions."
Mr Davies said he was concerned about the lack of progress on some of these issues.
"Taking the right actions in future will save public money, help tackle climate change and inspire others to act on sustainability," he said.
"If Wales is to become a truly sustainable country then government must lead by example, so I am pleased that the Welsh Assembly Government has commissioned the SDC to carry out this assessment annually from now on."
The SDIG process in Wales mirrors the SDC's work in other parts of the UK and some comparisons can be made, it said.
Wales is out-performing the UK government on waste but currently performing worse on water consumption.
Ms Davidson, the environment minister, who has been representing Wales at the Copenhagen climate summit, said the assembly government was the first devolved administration to undergo this scrutiny.
She said she hoped this would encourage all public bodies to be open about their environmental performance.
"The Welsh assembly government have made significant progress over the last year," said Ms Davidson.
"We must maintain this momentum and we will address any shortcomings.
"We have now signed up to the 10:10 campaign to reduce by 10% greenhouse gas emissions from our estate."