The European Union has launched a €35 million (US$39.4 million) tender to fund research and coordination on, among other things, detecting rogue efforts to alter the Earth’s atmosphere by blocking out the sun.

The EU’s Horizon Europe arm, which funds research and innovation, launched the call for projects on Tuesday as part of an early stage effort to coordinate action on so-called Solar Radiation Modification, a nascent and controversial technology that could be used to cool the planet should temperatures rise to critical tipping points.

In a report last month, the UN warned that global temperatures are set to cross the key 1.5 degrees Celsius (1.8 degrees Fahrenheit) threshold above pre-industrial levels within the next few years, and could climb as high as 2.6 degrees without changes to current policies.

The effects of climate change are already being felt with wildfires, droughts, hurricanes and severe floods happening increasingly frequently.

That has led to concerns that governments or private actors could launch unsanctioned experiments to try and alter the climate at a regional or global level with potentially dangerous side effects.

So far there is little in the way of international agreements to control or monitor such a move, and some scientists have called for an international non-use agreement on such solutions.

“This robust monitoring framework should be designed to detect and attribute outdoor experiments and deter potential unilateral deployments by private or state actors,” the tender published by the EU said.

The tender makes clear that deployment and field experiments are out of the scope of the project.