In the modern understanding, a national constitution sets a boundary around government. The environment – the notion incorporated in terms like “environmental protection” – is something that is not clearly unbounded, something that might encompass the whole planet. Constitutional government and environmental protection are potentially at odds.

It’s true, of course, that constitutional states have always enacted laws that we might now call “environmental protection” measures – for example, to guard water sources from contamination or to guard wildlife from excessive hunting. But we are much more concerned about “environmental” issues in the past few decades. The term itself, as an open-ended reference to overall natural or physical surroundings, did not come into general use until the mid-20th Century.  

Citizens in democratic countries disagree on the relative priorities they would give to protecting air and water from pollutants or wildlife from various threats, comparing limiting with costs that burden economic growth or personal freedom. Different countries have different priorities, with less affluent countries usually putting more priority on economic growth.  

We might say different countries should then be left to choose for themselves how demanding or ambitious their environmental regulation. But pollutants can drift over borders. And some environmental hazards may affect everyone – as with, it is said, the buildup of greenhouse gases (especially carbon-dioxide) in the earth’s atmosphere; gases that trap heat and encourage a long-term warming trend. To deal with such problems, environmental advocates urge international regulation. What if many countries don’t want to go along with - or don’t embrace - such protective measures through their own constitutional processes?

Citizens in democratic countries disagree on the relative priorities they would give to protecting air and water from pollutants or wildlife from various threats, comparing with limiting costs that burden economic growth or personal freedom. Different countries have different priorities, with less affluent countries usually putting more priority on economic growth.  

Some environmental advocates have had quite ambitious visions. The UN’s 1972 Stockholm Conference on the Human Environment (the first international conference to focus on the global “environment” – all of it) generated a Declaration of Principles to guide future policy. Among other things, it urged that states “should reduce and eliminate unsustainable patterns of production and consumption and promote appropriate demographic patterns” (Principle 8): put more plainly, reduce standards of living and reduce population growth.   

If that’s what “environmental protection” means, a lot of us will resist it. How will we decide how far to go? Environmental advocates look for ways to establish global strategies, which compel individual nations to go along with the kinds of controls others think appropriate. That approach will come under a lot of challenge in the next few years. Here are three central examples of emerging challenges to global approaches to environmental consensus. 

President Barack Obama favoured global agreements on reducing carbon emissions in ways that, advocates hope, may forestall climate trends. He did not present the US commitments in a formal treaty, since that would require ratification by a two-thirds majority in the Senate. Instead, President Obama endorsed the December 2015 Paris Accords on his own authority as president.  President Trump may withdraw that endorsement. Either way, we are likely to see litigation in US courts over the extent to which this sort of international venture can be cited as the ground for domestic regulation (as, in Obama’s plan, to force the closing of coal-fired power plants) when there is no clear authorisation from the US Congress.

Meanwhile, Britain will be negotiating its withdrawal from the European Union. The United Kingdom is now subject to a vast mass of environmental regulation required of EU member states by regulations or directives of the European Commission. Can the UK Parliament repeal or modify this body of environmental regulation – even after the UK resumes its status as an entirely sovereign nation? What if the EU demands that Britain continue to adhere to European environmental standards, as condition of full or generous access to European markets?

The results of that discussion are not likely to be limited to Britain. Since the World Trade Organisation was established in 1995, many environmentalists have protested that its trade rules give unfair advantage to countries that have more relaxed environmental standards than other countries. Industry that has to operate in countries with more demanding standards will face higher production costs, so will have to charge more for its products. Environmental advocates have urged that countries with higher standards should be allowed to impose compensating tariffs on exports from countries that allow producers to operate with less environmental controls.  

If that’s what “environmental protection” means, a lot of us will resist it. How will we decide how far to go? Environmental advocates look for ways to establish global strategies, which compel individual nations to go along with the kinds of controls others think appropriate. That approach will come under a lot of challenge in the next few years. 

Developing countries have protested against such proposals. Just behind environmental advocates are a line of others demanding protection for what they say as worthy forms of social regulation – minimum wage laws, compulsory health insurance or safety regulation, all sorts of regulatory measures which increase the cost of production in countries that maintain them and might give an advantage to producers in countries which don’t. If we allow compensating tariff protection for environmental measures, why not for others?  Very quickly, we will have forfeited the main benefit of free trade – allowing consumers to find cheaper products from places which can produce more cheaply. We will certainly place a heavy burden on developing countries, which can’t afford all the same range of social regulation as more affluent countries.

The World Trade Organization has spent two decades resisting such measures, trying to defend the principle that trading states can limit imports when they object to characteristics of the project (as unsafe for consumption) but not from objections to the way it is produced. If this principle fails, the way seems open for a great mass of protectionist legislation.

Here is a proposal for moderating the coming confrontations:  let’s return to constitutional process. Two related principles could go far in easing the strains of the present era. First, insist that every nation makes its own law (or at least, every nation outside the EU). That is the general US practice. Decisions of international conferences, even decisions of international courts, do not change US law until Congress or state legislatures enact such changes. Some courts and commentators have concluded that any other approach would violate the US Constitution, by transferring legislative authority outside the control of the constitutionally designated organs.

A related principle should be respected by states in their trade policy. States should not use trade restrictions to control the way other states produce export goods. States can, of course, demand that imports satisfy the safety standards they think appropriate to protect their own consumers. But how another state produces good in its own territory should be its own choice – unless there is some widely subscribed international treaty laying down relevant standards. That is the current doctrine of the WTO’s Appellate Body and it makes sense.

It would be a very bad idea to let states impose financial penalties on less developed countries to coerce them into higher environmental standards. Among other objections, the result may not be more environmental protection but merely reductions in trade, resulting in slower economic growth in poor countries. 

Rich countries might try to persuade less developed countries to adopt more ambitious or effective environmental controls by offering technical and financial assistance (as a number of major environmental treaties promise). But it would be a very bad idea to let states impose financial penalties on less developed countries to coerce them into higher environmental standards. Among other objections, the result may not be more environmental protection but merely reductions in trade, resulting in slower economic growth in poor countries – and poor countries tend to be less attentive to environmental protection.

Britain should try to resist an exit agreement with the EU that commits it to maintain EU environmental regulations which its own parliament may wish to change – and which don’t correspond to any generally accepted treaty. The United States should not be bound to implement international “agreements” not endorsed by Congress. Less developed countries should be encouraged to improve their environmental standards but not bullied by threats of unilateral trade sanctions from rich states.

To pursue environmental goals at any price is fanaticism. One of the main aims of liberal constitutions is to encourage compromise and consensus. We should not let environmental enthusiasm undermine those aims by side-stepping constitutional processes.