Sea level rise is going to take a while. Not much to worry about at the moment but I wouldn't buy oceanfront property anywhere. Its a huge and immediate concern in the Pacific where a number of islands are already gone or uninhabitable because of it, but for us big island folk and mainland folk its going to take a while to have a noticeable affect.
There's good news and bad news on that, too, according to the latest climate modelling - which is getting better each iteration but is hardly perfect. The good news is that the alarming sea level rise predicted several years ago (up to 30 feet) is not accurate: its more like 9 feet. The bad news is that it is probably inevitable. Climate change has been set in motion and our only options at this point are to slow it's progress, slow the pace at which weather events get increasingly severe and prepare for additional emergency costs on a regular basis. And that is what the SCIENTISTS are saying, not the environmentalists.
If you are wondering how this could be true and how the US government could have poopoo'd if for decades you have but to understand 1 thing: NOAA, the government's science arm that is more or less solely responsible for weather and climate records, is under the Department of Commerce.
Yes NOAA, the National Oceanic and Atmoshperic Adiminstration, is part of the government's machinery for making sure goods (and money) can keep moving. The movement of goods (and money) these days is facilitated by fossil fuels. We can't be recommending that people use less fossil fuels - that would be very bad for commerce. So the scientists were asked to identify other sources of CO2 and barred from making alarming predictions. I know some of these guys: their blood pressure is very high from watching this happen and not being able to say anything about it for fear of losing their jobs.
Trees and plants consume CO2 during the day but they exhale most of it at night. What they do is store a fair amount of carbon in their bodies. Much of that carbon is released back into the air (and some into the ground, which is good) when the tree dies. Trees sequester carbon by growing and keep it out of the atmosphere for the duration of their lives. Deforestation does 2 things: it reduces the amount of carbon sequestration by turning what was a carbon sink (a forest) into a much lesser one (a farm, usually) and the cut trees are sometimes burned - putting that carbon entirely and immediately back into the atmosphere.
Another major carbon sink is sea life. Most sea life gets the carbon for their bodies from atmospheric CO2 mixed into the water. When they died their bones and shells generally take that carbon the bottom where it stays for a looooong time. Less sea life = less carbon being stored = the oceans are less able to sequester carbon at the same rate they used to.
We have only 1 problem: there are way too many of us to continue living as we are now. The world can sustainably support about 20 billion people living at 3rd world, almost entirely vegetarian, levels. It can support about 2 billion people living at a Western European (NOT American) level of consumption. We're at just over 7 billion now. If they all want to eat steak then we have to have a lot of cows - more cows than there have ever been - and that means more methane production than there has ever been. :shrug: Sooner or later one of those 2 things WILL change: there will either be less people or less of them eating cows. Same for use of wood, fossil fuels, fresh water, etc.
How do you prepare? Not much you can do. Best thing to do is to localize your food, water, and energy production as entirely as you can. If what you need comes from far away then it will eventually become too expensive to get. There are a lot of political and economic pressures against doing that on any meaningful scale, though, so its not likely to happen.
Also prepare for increasing regularity of increasingly severe weather. Dry places are likely to get drier and wet places are likely to get wetter. Here in the tropics things won't get too much warmer - a few degrees on average - but the net effect will likely be more hurricanes and higher winds over all. Temperate climate will have likley experience more extreme swings from hot to cold over the course of the year: hotter, drier summers and more severe winter storms. Community emergency plans should reflect this. And get used to the idea of community emergency plans - they are likely to be very important in our lifetimes.