Will the world's poor start to suffer even more?

Your first question is yes, they will suffer more as everyone will if the full global warming takes place.

As to protecting them, I'm not sure what anyone can do.  From what I can gather, most nations themselves can not "protect" themselves from global warming.  And for nations economies that are developing to our level, they want everything that we have: fridges, cars, good medicine, running water, etc.  I doubt any western nation would really want to be a hypocrite about any of this, or feel they should again tell people what to do when they won't do the same practice towards their own people.

The one change that will need to take place, is to have economies, markets, nations and corporation measure the bads that they export.  In economics, just as goods are measured, there are bads (products or services that have a negative value or price in the economy).  Many times, bads are only regarded as the opposite of a good, but there is the theory that many goods produced also have an attached bad that is excluded from the calculation of the net value of normal goods and treated as an externiality.  For instance, gas and cars are treated as a good, and the bad is not calculated at any points within the GDP.  In fact, the disposal of the car is treated as a good as it produces a net gain to the GDP for the services rendered.  

So the true economic costs for a product and service would be best so that firms and economic agents (such as a customer) would know the true cost to their economy. 

There are so many ways to help to poor, the challenge is how to make this help  provide them  a  stable base for the future.  Most of the aid  we know if it's donations of any kind, are only short term solutions.  Any many of these cases its not enough to rely on peoples good will . Any help from the administration might have better effect . As a society we need to keep our hearts open. Volunteer, contribute etc. Understanding that there might be some need for taxation to help the poor. It will make us feel better and ,maybe create a new norm. As climate may cause a lot more damage to the poor , one of the solutions is to get the poor of the street. Building shelter homes which have to be governmentally founded  is a good one. I think creating an option for citizens to respectfully provide for there families  will be a good long term solution.