The margarine Martin Persson spreads on his sandwiches each morning doesn't keep him awake at night — but it does taste lightly of guilt.

Persson, a scientist at Chalmers University in Sweden who follows a vegan diet, knows his innocuous breakfast spread helps devastate forests about ten thousand kilometers away.

Along with beef and soy, palm oil in margarine and other everyday foods have long been known to accelerate deforestation in countries such as Brazil and Indonesia.

Now, Persson and an international team of researchers have quantified how much foreign demand for commodities drives that destruction.

The study, published last week, found that 29-39 percent of the carbon dioxide (CO2) released through deforestation is driven by international trade — with farmers felling forests to clear space for croplands, pastures and plantations that grow goods often consumed abroad.

In many rich countries, the authors wrote, the deforestation-related emissions "embodied" in imports are greater even than those generated by domestic agriculture.

"It's not [just] the consumers in the countries where deforestation takes place who cause it — it's driven by consumers elsewhere," said Ruth Delzeit, head of environment and natural resources at the Kiel Institute for the World Economy (IWF).

That matters for counting CO2 emissions and deciding whose responsibility they are.

"The way the UN has countries report emissions is where they're produced," said Jonah Busch, chief economist at the Earth Innovation Institute. In Germany, for instance, that means emissions from domestically-grown grapes count as Germany's — but emissions from margarine made with palm-oil imported from Indonesia do not.

Deforestation second-biggest source of greenhouse gases worldwide

The gutting of the earth's forests, which remove and store CO2 from the atmosphere, is a major hurdle in the fight to slow climate change. It is made worse, experts say, by complex supply chains that distance consumers from the damage wrought in making their goods.

To estimate carbon footprints from deforestation for countries and goods, the research team in Sweden combined trade flow data with satellite images of changing land use from 2010-14. They did not attribute forest loss from non-agricultural activities — such as mining, urbanization or natural forest fires — which cause about 40 percent of deforestation.

In Africa, they found almost all emissions related to razing forests stayed within the continent. But in Asia and Latin America, considerable amounts of the CO2 released through burning and chopping trees were effectively exported to Europe, North America and the Middle East.

Whose responsibility?

The accounting gap between where CO2 is emitted and where the products that release it end up raises difficult questions about who should deal with them.

"You could say the EU is only a minor part of the problem," said Persson, referring to the high share of consumption that did not leave tropical regions but was instead consumed domestically.

The bulk of deforestation emissions came from just four commodities: timber, beef, soy and palm oil. In Indonesia and Brazil, the fourth- and fifth-most populous countries in the world, palm oil and beef have huge domestic markets.

The European contribution is still significant, said Persson, because "in the EU we want to reduce our own impact on climate change — and this is one important and dominant part of our impact."

In a challenge to traditional carbon dioxide accounting practices, the researchers estimated about one-sixth of the CO2 released into the atmosphere from a typical European diet could be linked to deforestation in the tropics through imported commodities.

"That was a surprise for me," said Persson. "Yes, we do import a lot of food, but most of the food we consume in the EU is domestically produced."

Brazil exported a record-breaking 1.64 million tonnes of beef last year, data from the Brazilian Beef Exporters Association show, which is up from 1.48 million tonnes in 2017. Indonesia, meanwhile, is the world's biggest producer of palm oil, which increasingly pervades everyday supermarket goods ranging from bread to soap.

"Palm oil is one of the largest export commodities, so one can trace the deforestation effects of those trades and [see] it has a huge impact on Indonesia," said Ahmad Dermawan, a scientist with the Center for International Forestry Research (CIFOR).

In addition to spewing CO2, the burning and felling of forests can also cause displacement, habitat loss and flooding. In Brazil, indigenous land has been stolen to clear way for farms. In Indonesia and Malaysia, more than 100,000 orangutans have been killed since 1999, according to a study published last year.

Rising consumption

Experts fear deforestation and the associated destruction will continue to rise as middle-income countries grow richer.

India is already the biggest importer of Indonesian oilseed products. Last year's rise in Brazilian beef exports, meanwhile, was driven by a 53 per cent increase in Chinese demand from 2017 to 2018, data from the Brazilian Beef Exporters Association show.

"We can see that exports to India and China will increase massively in the future [as they become] richer per capita," said Delzeit, of the IFW. "They will move towards western diets — which includes increasing the consumption of meat."

That has consequences for richer nations who might argue their contribution to deforestation is proportionally small.

"The EU and US set a global standard that is increasingly being heard in China and India and other emerging markets," said David Kaimowitz, director of natural resources and climate change at the Ford Foundation. "If they see companies or countries that import a lot of deforestation in their products being publicly criticized or held to account, that does filter through to their own policies."

Palm oil, soy and beef markets are dominated by just a handful of multinational companies, some of which are headquartered in Europe and North America.

"If the EU can pressure them to change their production practices, that can have an impact on other countries," said Persson.

But a recent EU move to classify palm oil in biofuels as unsustainable, partly due to public concerns about deforestation, has led to fears of a trade war erupting between the bloc and the world's two biggest palm oil exporters, Indonesia and Malaysia. They have accused the EU of protectionism by targeting palm oil without addressing concerns associated with cultivation of less-efficient vegetable oils, such as rapeseed.

Darmin Nasution, Indonesia's coordinating minister for the economy, said in a press briefing in Brussels this month it was "ironic" that the EU, which has cut down a much larger share of its forests, was giving tree-rich countries forest management advice. He also pointed to palm oil's contribution to poverty alleviation.

"The framing from the European perspective is the deforestation, land use change and so on," said Dermawan, of CIFOR. "But from the Indonesia perspective it’s about smallholders, development and livelihoods. That should be discussed and connected too."