International shipping and aviation emissions have been excluded from the new draft climate agreement being negotiated at the United Nations Climate Change Conference (COP 21) in Le Bourget, Paris.
During the five-day climate talks in Bonn, Germany, the sectors were revealed to have been included in the Paris agreement draft to be signed in December.
However, environmental groups including Seas At Risk and Transport & Environment (T&E) earlier speculated about the draft agreement having excluded the aviation and shipping sectors from targeted CO2 emissions cuts.
T&E policy officer Andrew Murphy said: "The dropping of international aviation and shipping emissions from the draft Paris climate agreement makes keeping a temperature increase less than 2° close to impossible.
"Those parties calling for an ambitious agreement must insist that language on international transport be reinserted."
The environmental groups also claimed that previous calls for aviation and shipping CO2 reduction targets will be removed under the draft Paris deal.
According to the International Maritime Organisation (IMO), carbon emissions from international maritime shipping could increase by 250% in the period to 2050 if left unchecked.
The International Chamber of Shipping (ICS), which represents the global shipping industry, recommended the UN IMO enforce further regulations to curb CO2 emissions across the global merchant fleet.
ICS secretary general Peter Hinchliffe said: "Mandatory regulations already adopted by IMO will ensure that all ships built after 2025 will be at least 30% more efficient than ships operating today.
"Combined with further technical and operational measures plus new technology, international shipping should be able to reduce its CO2 per tonne kilometre by 50% before 2050."
With the least developed countries likely to suffer the most from the consequences of climate change, IMF and World Bank expressed strong dissent against such levies.