Consulting firm Wood Mackenzie estimated on Thursday that global investment of $2.7 trillion a year is needed to reach net zero emissions by 2050 and avoid a rise in temperatures of more than 1.5 degrees Celsius this century, Reuters reports.

Scientists have warned that the world must limit the increase in the global average temperature to 1.5 degrees Celsius this century to avoid the catastrophic effects of climate change. Many governments have pledged to reduce carbon emissions to net zero by the middle of this century.

However, the Wood Mackenzie report shows that most countries are not on a trajectory to meet their emissions targets by 2030, let alone the 2050 targets.

Net zero emissions means reducing emissions to a level as close to zero as possible, and any remaining emissions will be re-absorbed from the atmosphere, for example by oceans and forests, according to Agerpres.

Wood Mackenzie estimates that decarbonising the energy sector needs investments of $1.9 trillion per year, and that these investments must be increased by 150% “or $2.7 trillion per year” to limit global warming to 1.5 degrees Celsius . Three-quarters of these investments are needed in the electricity supply and infrastructure sectors, including renewables and transport systems.

“Achieving the 1.5 degrees Celsius target will be extremely difficult but it is possible and largely depends on actions taken this decade,” said Wood Mackenzie president and chief analyst Simon Flowers.

Renewables, such as wind and photovoltaic power, must become the world’s main source of electricity supply to support the electrification of transport and the production of green hydrogen, say analysts at Wood Mackenzie.