Northern Ireland urgently needs 2,000 hectares of trees planted every year until 2025 to help reach zero carbon emission targets, conservationists have warned.
The Woodland Trust has published a report revealing only 240 hectares were planted here during 2018-19 - 1,760 hectares less than its proposed target.
The charity said its emergency plan is the first of its kind and has been compiled as a "challenge to governments" by outlining how each UK region can increase tree cover to "reach zero net carbon emissions".
The increase in the number of trees would also help tackle the decline in wildlife.
Overall the UK needs 35,000 tree hectares planted annually over the next five years, according to the trust.
Broken down by region, Scotland requires the highest number at 18,000 hectares, followed by England (10,000), with Wales in third (5,000) and Northern Ireland fourth (2,000).
However, the actual number of hectares planted across the UK amounted to 13,390 - less than half the number needed, the charity said.
The organisation is also calling for emergency government resources to increase tree cover, which it says needs to more than double annually, starting this year.
Darren Moorcroft, chief executive of the Woodland Trust, said the start of this year has begun with "more woods under threat from destruction than any other time in history".
"Tree planting rates are the lowest in decades, and one in 10 wildlife and plant species is under threat from extinction," he revealed.
"Disease and pests have taken hold and risk to wipe out millions of our native trees. Never has the picture appeared bleaker."
Warning there is a "phenomenal amount to do in a very short space of time", Mr Moorcroft stressed the "moment of crisis has come".
"Government needs bold policies and local authorities and landowners need the support to act swiftly and to expand tree cover across the UK," he said.
"I cannot stress enough that we can't be here in the same position next year for all our sakes."
The charity chief urged political parties who made pledges during the election campaign to plant trees to "urgently translate" their ambitions into "action".
This includes expanding native woodland, increasing sustainable commercial plantations as well as hedges and individual countryside and urban trees.
According to the charity, the UK has just 13% tree cover compared to the European average of 37%.
Mr Moorcroft said increasing tree cover must be done with careful consideration.
"Previous governments have tried to dramatically increase tree planting rates before," he claimed.
"In doing so, some of our finest wildlife sites were damaged.
"We can't afford to make the wrong decisions about how and where we expand tree cover. We don't have time."