Donald Trump’s decision to pull the United States out of the Paris Climate Change Agreement poses a very stark question for Irish agriculture.

And this is it: Why should farmers in this part of the world ‘knock their pans out’ striving to reduce methane and other greenhouse gas (GHG) emission levels, while their counterparts in the US have free rein to do whatever they wish?

This situation is inherently unfair and should be actively addressed by the European Commission and other relevant authorities around the world, including the World Trade Organisation (WTO).

A proportionate response, in my opinion, would be to introduce a levy on all US food exports to those countries that have signed up to the Paris Accord. Let’s be clear about this: There is a significant cost for Irish farmers as they strive to comply with the likes of Bord Bia’s ‘Origin Green’ initiative. And, no doubt, measures of this nature are being replicated in other parts of the world.

All decisions have consequences. So it is only fair that US farming and food should incur a meaningful degree of discomfort, in light of Trump’s decision to exit COP 21.

The consequences of such a move would also help bolster the fortunes of Irish agriculture – milk in particular. America’s dairy sector is a major world exporter. Moreover, it is an industry with a tremendous capacity for growth, particularly at times when world grain prices are cheap.

The introduction of an ‘environmental levy’ on US exports would, therefore, create a more level playing field for Irish food companies as they strive to increase their presence in international markets.

And the same principle holds for beef, lamb, pork and the other food products that are exported from Ireland.

The corollary to all of this is that the US will introduce its own levies on food imports. But such a move is hardly likely to give Irish food exporters much cause for concern, given their slow rate of progress in accessing that market.

Moreover, Trump scuppered the proposed Transatlantic Trade and Investment Partnership (TTIP) – a trade deal between the US and the EU – within days of coming into office.

And the track record of Irish beef processors accessing the US market with product, particularly in the wake of all of the work put in to secure access in the first place, has been pretty underwhelming.

In short, Trump should face Newton’s Third Law whereby actions are met with reactions.