Global warming is a reality and has been for some time. The average atmospheric temperature today is about 57° Fahrenheit and increasing. To arrest this trend, the international community hopes to achieve agreement to cap the increase at no more than 3.5° F above and ideally less.
Sea-level rise is one of the major consequences resulting from climate change. It is driven by two factors, a heated ocean and melting of landbound ice (ice already floating on the ocean does not increase sea level as it melts). At present, the single largest cause is ocean thermal expansion due to atmospheric heating.