Good question. One possible way would be to start building such a concession into future bilateral agreements between states where one is particularly 'vulnerable' to environmental degradation.

Most of these agreements would be trade agreements, and in some cases (such as NAFTA) there would be an Environmental side-agreement. So in summary, taking advantage of existing policy structures and expanding them to capture this new problem of environmental refugees may prove fruitful.

That's a good question to a very current problem.

As usual, countries can either do what they think it's best for them (Australia and New Zealand, in this respect, lead the way in the Pacific) or follow a broader international consuetude. Such a thing - with such a scope - does not exist yet, meaning that, unfortunately, it's up again to the UN or another supranational organization to take the first, surely controversial, step. An ad hoc committee would be something to start with. The introduction of amendments to bi-multilateral agreements, suggested by Jean-Paul Huteau Skeete, would be good too, altough I think it's quite unlikely they would be implemented, as they might reduce the economic benefit on both sides of the agreement.

The second part of your question regarding "Sovereignty of the States" is important and interesting. I am studying globalization. In recent age of globalization environmental issues are not limited to different states now these are global issues for example international law of seas etc therefore if you study recently concluded bilateral and multilateral agreements than you can find the answer of your question.

There is no such thing as "environmental refugees", which is a canard created by refugfee lawyers to extend their law practices, or bored law professors.

The 1951 Convention on refugees is very clear concerning the definition of a refugee: there must be a reasonable fear of persecution, and thus a persecutor. There is no persecutor in the case of "environmental refuge", unless you humanize the climate as a person capable of independent thought!

The situation of the people affected by oceanic changes - which have existed for millenia - must, and can, be dealt with through ordinary immigration mechanisms which are certainly much better suited than refugee law because they allow for rational processing of categories of individuals, instead of a case by cas treatment that is incoherent and unpredictable.

While it is true that the 1951 Convention does not recognize as refugees those forced migrants who flee because of environmental degradation or climate change, they nevertheless exist. There are therefore calls for amendments to - or, if you will, long overdue updates of - the international refugee regime. One example I would suggest you have a look at is the idea of "survival migrants", developed by Alexander Betts.

I have been a refugee judge for several years. I have given asylum to many men, women and children from many countries. BUT the present régime for refugee protection is terribly misadapted to reality: the real refugees have to live in squalid camps in neighbouring countries (look at Lebanon, Jordan and Turkey now) while the 1951 Convention has created a thriving emigration industry often supported - or even organized - by criminal cartels, and watered down the very notion of citizenship.

This notion of "survival migrants" is a great gift to dictatorships, which are more than happy to let us take care of their dissenters or minorities on our dwindling social and health budgets. The collapse of the immigration systems in Europe and the US under the pressure of millions of illegal immigrants is only the beginning of a very ugly development in local politics: the blossoming of reactionary and extremist parties of the left and right in reaction to massive flows of illegal immiigrants.

Finally, in my entire experience as a refugee judge I have NEVER seen any refugee claimant capable to base their claim on environmental degradation or climate change, or capable to bring any credible evidence in support of such claims.

I'm not sure whether you are defending the 1951 Convention, which your first answer indicates, or whether you want to criticize it, which your second answer indicates.

Either way, an example of a "survival migrant" would be a person forced to leave a pacific island disappearing under rising sea levels. This might not have happened yet, but it is not unlikely that it will happen in the near future. Such a person would be outside the country of his nationality and unable to avail himself of the protection of that country, because it no longer exists. However, because he wasn't persecuted he is not a refugee according to the 1951 Convention, and he doesn't have the right to protection provided by that Convention. How is the development of a legal standard for the protection of that person a gift to dictatorships?

Also (and please correct me if I'm wrong), I believe dictatorships have a tendency to persecute dissenters - particularly if they want them out of their country, for "us" to take care of. Such dissenters, in other words, are already covered by the 1951 Convention, and would therefore have little bearing on the concept of survival migration. 

The notion of "survival migrants" is a gift to dictatorships, because they simply have to make the living conditions for some segments of their populations so miserable, by the deliberate destruction of infrastructures, pollution of water and soils, etc., that the targetted groups would HAVE to migrate en masse in order to survive. Such encouragement of "quasi-genocide" was clearly NOT one of the intended results of the 1951 Convention! But it  has already happened numerous times, for example with the Meos in Viet-Nam in the late 1970s and the Kurds in Northern Iraq in the 1980s (Operation Anfal). Succintly: beware of "reverse interpretation" of international conventions by criminal régimes.

The hypothesis of disappearance of some Pacific islands under rising seas is precisely that: an hypothesis.

Right now, there are much bigger and immediate refugee problems, such as the genocides of the Yazidis and the Christians in Daesh-occupied regions of Iraq and Syria. And I am not even talking about the enormous burdens supported by Lebanon, Turkey and Jordan by taking Syrian refugees, or taking Palestinian refugees from Syria and Iraq. The expulsion of Palestinian refugess from Kuwait after the fall of Saddam in 1991 has been a precursor of this new tragedy for the Palestinians.

Better protection for the victims of persecution leads to more persecution?

Personally, I think criminal regimes, such as the ones you mention, couldn't care less about what happens to the people they force out of their countries. I doubt that the likes of Saddam Hussein would make sure there is adequate protection for their victims before they started to persecute them. If I'm right, a framework for the protection of forced migrants that do not meet the criteria of the 1951 Convention would be just that: a framework for the protection of people in need.

Now I don't intend to pursue this debate any further.

"Better protection for the victims of persecution leads to more persecution?"

Who said that? The 1951 Convention was created, like any legal instrument, with a specific purpose, or set of purposes, in mind: to protect specific individuals. It is important to respect such purposes, and that does not prevent the development of different tools for different situations.

"I think criminal regimes, such as the ones you mention, couldn't care less about what happens to the people they force out of their countries. I doubt that the likes of Saddam Hussein would make sure there is adequate protection for their victims before they started to persecute them."

They sure DO care about the fact that they have at least the appearance of legality on their side, and that they impose on democracies the financial and social burden of taking care of their victims! The nature of evolved dictatorships is precisely to develop such legal tools to protect their actions under the mantle of legality. I wrote a very detailed study about the processes developed by the judiciairies in Communist Afghanistan and in Baathist Iraq to develop a "dictatorial legality", which mirrors the processes developed by the Nazis and the Communists in the 1930s to reshape the judiciaries of germany, Russia, etc, to their extremist purposes ("Criminal Justice Systems. The criminality and the reformation of the Afghan and Iraqi justice systems"). On that topic, see also Ingrao, "Believe and Destroy. Intellectuals in the SS war machine" (2014).  I saw exactly the same process in Iraq, with the Baath, and Afghanistan, with the PDPA, as those described by Ingrao in Germany under the Nazi régime.

"If I'm right, a framework for the protection of forced migrants that do not meet the criteria of the 1951 Convention would be just that: a framework for the protection of people in need."

Yes, it is a good thing to protect "people in need" but it would be better in many cases to do it outside of the scope of the 1951 Convention. For example, problems of scale are extremely different when you are dealing with a situation on a case by case basis (1951 Convention) and when you are dealing with an entire population (catastrophic refugees); in the first case, you work at the individual level, whereas in the second you work at the family or "tribe" level. Just think about the administrative nightmare of THOUSANDS of individual refugee hearings.

"Now I don't intend to pursue this debate any further." Seriously?

thanks to all

There is no such thing as "environmental refugees" according to the 1951 Convention. 

If you are still working on this issue please have a look a the Nansen Initiative launched by Norway and Switzerland.

https://www.nanseninitiative.org

May I suggest a bunch of articles and chapters that my co-worker has written:

2015. "A Free Movement Passport for the Territorially Dispossessed", kommande i D. Roser & C. Heyward (red.) Climate Justice in a Non-ideal World. Oxford: Oxford University Press. [Med Clare Heyward].

2014. "Underwater Self-Determination: Sea-Level Rise and Deterritorialized Small Island States", Ethics, Policy & Environment 17(2).

2010. "Climate Refugees: Normative Problems and Institutional Solutions", i Hagiwara Yoshihisa (red.) Democracy and Governance for Civil Society. Tokyo: Fuko Press.

here are his profile:

https://www.iei.liu.se/stat/jorgen-odalen?l=sv