The Kyoto Protocol, the international treaty aimed at combating climate change, came into effect today more than seven years after it was first adopted.
However, critics have warned that as long as the United States refuses to sign up, the protocol will change little.
The treaty demands that more than 140 nations, which account for more than 60% of greenhouse gases, change their ways.
The Minister for the Environment, Dick Roche, has described Kyoto as a milestone, but warned that while it will reduce dangerous emissions, deeper cuts will be required over the coming decades.
Latest figures show Ireland's emissions, which are just under double what they are supposed to be, have been falling in recent years.
The Director General of the Environmental Protection Agency, Dr Mary Kelly, has said further measures on curbing the fastest growing sector, transport, will be needed if Ireland is to achieve its Kyoto commitments.
However, the Irish Business and Employers Confederation has voiced caution. It stated claims that if Ireland fails to meet its Kyoto targets the 'scare bill' of billions has to be rounded down to €40 million per annum.
Environmental campaigners, like Greenhouse Ireland Action Network, describe fossil fuels as a 'costly and dangerous poisoned chalice' while Friends of the Earth says, despite the current political agenda, taxing carbon fuels is essential.
