Championing a world-beating Climate Change Act was always going to be the easy part.

When the Scottish Government hailed its ambitious new greenhouse gas emissions legislation in 2009, it signalled a fervent desire to make Scotland an exemplar to the world.

Meeting its targets was always going to be much harder, however, and take all of the Scottish Government's collective resolve to achieve in the face of hostile economic circumstances. Just how hard was revealed last October when it emerged that the very first target under the Act, for 2010, had been missed.

Significant progress has been made in increasing the proportion of Scotland's energy needs derived from renewables, but that is only part of the equation when it comes to cutting emissions. Everyday energy use in homes and offices must also be driven down. Ministers' watering down of their ambitious but much-needed energy conservation standards for new buildings, therefore, gives serious cause for concern.

The delayed implementation and weakening of those standards is intended to ease the burden on the construction sector, one of the main casualties of the unforeseen banking crash and subsequent recession. It is clear that the move is having unintended consequences for another sector, the energy conservation industry. Andrew Warren, director of the Association for the Conservation of Energy, warns of "severe and damaging" impacts caused by ministers having gone back on what the industry believed to be a firm commitment to tougher standards.

Employers in the sector are understandably alarmed at the prospect that those already diluted standards could be watered down even further. Having raised investment on the basis that there will be a buoyant market for their products and services driven by tough new regulations, they fear for the future, for jobs, investment and exports.

Prospective house buyers, meanwhile, are also likely to be disappointed to hear that new buildings will have less stringent energy conservation standards; given the rising cost of energy, that means higher living costs for them.

Meeting Scotland's greenhouse gas emissions reduction targets will only become tougher in the face of this compromise. Ensuring thousands of new homes and offices are constructed to the higher standards could reap dividends for years to come in terms of lowering carbon emissions and reducing fuel poverty. Retrofitting further insulation to existing buildings is possible, of course, but the cost of doing so could deter future owners from making the improvements.

The Scottish Government signed off on its Climate Change Act fully aware of the uphill struggle it would face in achieving its targets but was determined to meet that challenge. Having missed its first target, it cannot afford to miss another without calling into question the depth of its commitment.

WWF Scotland has been calling for years for minimum energy performance standards to be introduced in homes to tackle energy loss and fuel poverty in existing as well as new houses. Measures such as this are essential if Scotland's Climate Change Act is to lead the world in fact where it has already inspired with words.