EXCLUSIVE: By Rob Edwards, Environment Editor

International scientists, campaigners and celebrities are piling pressure on the Scottish government to toughen its plans to tackle climate change.

First minister Alex Salmond, and other political leaders are being told by 13 top climate experts that the current aim to reduce emissions 34% by 2020 is "wholly inadequate". The target must be raised to at least 42% to help save the planet, they say.

The scientists' dramatic plea, to be delivered tomorrow, is the latest in an extraordinary global groundswell of voices putting mounting pressure on ministers and MSPs to strengthen their climate change bill, due for its final debate in the Scottish Parliament on Wednesday.

Business leaders, celebrities, politicians, trade unions, students, faith groups, community organisations and environmentalists have united with leaders and campaigners in developing countries such as Malawi, Ethiopia and the Maldives to demand tougher action from the Scottish government.

"Climate change is a global emergency," said president Mohamed Nasheed of the Maldives, low-lying islands in the Indian Ocean which could be drowned under seas swollen by melting polar icecaps.

"The world is in danger of going into cardiac arrest, yet often we behave as if we've caught a common cold."

Stop Climate Chaos Scotland, a coalition representing two million people in 60 organisations, accuses Scottish ministers of failing the world.

"Here is an unequivocal opportunity to demonstrate real leadership and it has come up short," said the coalition chairman, Mike Robinson. "Political posturing and expediency have ruled the day."

A spokesman for the Scottish government yesterday declined to respond directly to the demands for a tougher target. "The Scottish Government is taking forward the most ambitious and comprehensive climate change legislation anywhere in the world," he said.

"Our bill sets a target of reducing Scotland's greenhouse gas emissions by 80% by 2050. Scotland is well placed to meet these challenges."

Among the Scottish celebrities pushing for action are author Iain Banks, comedian Frankie Boyle and musician KT Tunstall. Boyle said: "All of us now have a once-in-a- generation opportunity to make a difference to the future of the planet."