The International Monetary Fund is calling on major greenhouse gas-emitting countries to implement carbon taxes that reach $75-per-ton by 2030 to bolster today's "inadequate" responses to climate change.

Why it matters: Their new report says the window for keeping temperature rise to manageable levels is "closing rapidly" and that "limiting global warming to 2°C or less requires policy measures on an ambitious scale."

What they found: IMF analysts measured the cost-benefit of CO2 taxes in the $25–$75 range and found carbon pricing would produce substantial emissions cuts and health benefits despite economic tradeoffs.

Taxes could be structured to mitigate burdens from higher energy costs, such as redistributing money to poor households, and to support workers "disproportionally affected" by the move to climate-friendly energy.

The big picture: The IMF is calling for carbon prices that are far higher than what has proven politically feasible thus far — something the authors acknowledge.

"About 50 countries have a carbon pricing scheme in some form. But the global average carbon price is currently only $2 a ton, far below what the planet needs. The challenge is for more countries to adopt one and for them to raise the price," the report authors note in a blog post.

The intrigue: It's not lost on the IMF that countries are hesitant to act unilaterally for fear of hurting domestic industries.

The report proposes an "international carbon price floor" to tackle this, and say that even a floor well below $75 would yield big gains.

A $50 floor for advanced nations in the G20 and $25 for the group's developing economies would cut emissions 100% more than those nations' current pledges under the Paris agreement, the blog post states.

Go deeper: The world needs a massive carbon tax in just 10 years to limit climate change, IMF says (The Washington Post)