Countries’ pledges to reduce their greenhouse gas pollution rely on impossible amounts of tree planting and distract from the necessary focus on emissions reduction, a new report warns. “Countries are loading up on land pledges to avoid the hard work of steeply reducing emissions from fossil fuels, decarbonizing food systems and stopping the destruction of forests and other ecosystems,” Kate Dooley, the lead author of the “Land Gap Report” and a researcher at the University of Melbourne, told Inside Climate News.

In order for countries to meet their pledges, officially known as Nationally Defined Contributions (NDCs), would require 4.6 million square miles of newly forested land — approximately the size of the entire U.S. and Mexico.

“Countries treat land like a limitless resource in their climate plans,” Kate Dooley, lead author and a researcher at the University of Melbourne, told Reuters. “Using a land area equivalent to half of current global croplands for tree planting simply won’t work.”

Though not quantified in the report, businesses’ voluntarily adopted “net-zero” plans — to they extent they are transparent about their pathways at all — also rely on unrealistic assumptions of tree planting to pull CO2 out of the atmosphere. “Corporations are currently pushing for scale in the voluntary carbon markets to service claims of carbon neutrality, but no one is doing the math on what is actually possible,” said co-author Jens Friis Lund of the University of Copenhagen. (Reuters, Inside Climate News, Mongabay; Carbon markets: Washington Post $; Corporate opacity: E&E $)