There are about 100,000 Samis -- considered Europe's last indigenous population -- many of whom live from traditional reindeer herding, which requires vast open spaces.

But the expansion of infrastructure for renewable energy production and mineral extraction is hindering their ancestral ways of living, said the report, which Amnesty International drafted in partnership with the non-governmental Sami Council.

"Climate change threatens the culture and existence of the Sami indigenous people in two ways," it said.

"Firstly, through direct environmental impacts such as changing weather conditions and ecosystems, and secondly, through the increasing number of energy projects and resource extraction... in the name of 'green' development and 'clean' energy transition."

The Samis and their migratory herds are spread across the vast open spaces of Arctic Finland, Norway, Russia and Sweden.

The report -- entitled "Just transition or 'green colonialism'?" -- takes the example of the Fosen wind farms in Norway, where 151 turbines were installed on what opponents said was traditional reindeer habitat.

Norway's Supreme Court later ruled that the construction of the turbines was illegal, since it had no valid licences, and that it was violating Sami people's rights as granted by the United Nations.

- Warming Arctic -

The case triggered a vast mobilisation of environmental and Sami activists, who demanded the turbines be demolished.

It ended with a financial settlement with herders.

The report highlighted other conflicts surrounding mine projects in the Swedish village of Ronnbac, and in Kasivarsi, Finland -- both of which threatened reindeer herding, it said.

Amnesty and the Sami Council urged authorities in Nordic countries to increase consultations with Sami populations and seek their agreement before granting any new infrastructure projects that could infringe on their rights.

These disputes add to the direct effects of climate change, which in the Arctic manifest themselves three or four times faster than elsewhere in the world.

Among other challenges, temperatures are rising, with "frequent temperatures around 0 degrees Celsius (32 degrees Fahrenheit)".

If rain falls on existing snow, it freezes and forms an ice crust over the surface, meaning reindeer cannot reach lichen, their main food source.

Early ice melting means river crossings are not covered by sufficiently solid ice or are flooded, making herding and reindeer migration perilous or even impossible.