In Latin America, as elsewhere, progressive governments of the centre and left struggle with a seemingly intractable dilemma: should the country exploit its natural resources to the fullest, no matter what the consequences – or consider ethical questions such as the wellbeing of the natural environment and future generations?

Countries such as Colombia, Ecuador, Bolivia, Argentina and Brazil hope to benefit from the commodity boom in global markets, fuelled by demand in China and elsewhere. At the same time their constitutions, as well as the manifestos of progressive political parties, pledge allegiance to a whole new variety of non- and post-human rights – rights of nature, declarations of inter-generational justice, and the recognition of Amerindian cultures.

These cultures are being celebrated in Beyond El Dorado, an exhibition at the British Museum in London. It includes hundreds of gold objects excavated in the early 20th century; and ceramics and stone necklaces from the Museo del Oro in Bogotá – which has one of the best collections of pre-Hispanic gold in the world – and the British Museum's unique collections.

The British public has responded en masse to the profound spiritual and aesthetic message expressed by the gold objects displayed in the museum. But now it is time to consider the ethical and political implications of that message: not as a relic of the distant past, but because it may contain some of the answers we desperately seek to the most relevant questions of our time. A discussion organised by the Guardian and the British Museum next month aims to do just that with the help of a distinguished panel.

These big questions – climate change, food security, equality – are already being discussed in Latin America thanks to the social movements that are helping to remould politics and political discourse. In these countries both the electoral survival of progressive parties and the continuity of crucial processes of reconciliation and democratisation depend on the support of increasingly active social movements. These often include rural as well as urban campaigners, concerned about the social and environmental devastation caused by global market forces.

In this respect, social movements in the Americas display an attitude that cannot be dismissed simply as backwards or anti-business. They demonstrate a legitimate critical attitude towards the contradictions inherent in processes of globalisation. And rather than withdrawing into some fantasy zone, these movements seek to engage actively with the state and transform the relationship between the state and the people from within.

The concept that explains this interdependence between social movements and progressive parties in government goes by the name of "dual power": the underpinning of vertical state-citizen relations by horizontal social movements, ready to criticise the decisions of the parties they elect on the basis of a commitment to a progressive agenda. This is how the protests that rocked the politics of countries such as Colombia, Brazil, Chile and Bolivia last year must be understood: as manifestations of dual power, and expressions of the terms of a new social contract – one that includes nature not only as a reservoir of resources but as an agent of politics and of the wellbeing of society.

As far as these movements are concerned, democracy and ethical politics go hand in hand. They discuss the big questions of our time – climate change, food security, the role of commons, the rights of nature, equality – in a political arena that until recently appeared to offer no alternative to the "one size fits all" view of globalisation and the market.

Crucially, in most Latin American countries such dogmatic views were imposed by sheer force, either military – as in Chile, Brazil, Argentina or Bolivia –or paramilitary, as in Colombia. To most Colombians it is now clear – a matter of indisputable record – that the paramilitary violence that engulfed the country with peculiar intensity during the last decade and a half, with the leading intervention of the United States, was part and parcel of an economic project rather than solely a counter-insurgency exercise.

The model still in place depends on the unbridled extraction of natural resources from parts of the country that have traditionally sustained peasant, indigenous and Afro-Colombian ways of life, and is the result of such violence. Because of this, as far as the social movements are concerned, any peace process worthy of the name must also consider the serious ethical questions posited by climate change science, food security and so on.

According to the information provided by climate science, as well as from anthropology and the humanities, it is no longer possible to keep human history separate from the history of the planet. We have become geological agents, capable of affecting and even destroying nature as a whole. We do this through the very processes that we considered to be at the heart of freedom in the 20th century – chief among them free trade. What we need now is a new politics, not only a politics of freedom, but one of post-human rights and cosmopolitics.

• A panel discussion – Colombia's resources: blessing or curse? – will take place at the British Museum on 13 February at 8pm