As citizens in the United States witnessed during Hurricane Katrina, the city of New Orleans was nearly submerged completely underwater. The torrent was seemingly unstoppable as the levees broke, unleashing water up to or more than 11 feet from ground level.

The city recovered, as we all know, but there are island and non-island nations around the world that already know that their time may be up. Rising sea levels have already eroded away parts of their coast and hampered their crop production, adulterating their stores of fresh water with oceanic salt water. Here are five countries that probably won't be around by the end of the century:

1. Tuvalu: The Prime Minister of Tuvalu, Enele Sopoaga, has been working tirelessly since his election to forward some kind of climate change resolution in the United Nations to save his country. Unfortunately, the country has been losing some of its coastline every year, and the island of just over 10,000 residents will likely have to evacuate in the decades to come. There have been major efforts by neighboring countries, such as Australia and New Zealand, along with the European Union, to keep the country afloat, but should global temperatures continue to rise, the island chain will likely be submerged.

2. Kiribati: The small island chain in the South Pacific is one of the most likely to be gone by the end of the century. It comes as no surprise that the crux of its foreign policy is based on climate change and its work through the Alliance of Small Island States (AOSIS). President Anote Tong has openly stated that the islands may be uninhabitable by 2050 due to salination of their water supply, and by eventual flooding. He has stated that emigration away from Kiribati should begin immediately.

3. Maldives: Located between India and Africa, the Maldives have been ranked as the third-most in danger from climate change. The former president of the Maldives, Mohamed Nasheed, has pleaded in the past for some kind of action to be taken to curb global carbon emissions. In 2008, President Nasheed looked into buying land in South Asia so as to transplant all the residents of the Maldives before the islands are submerged.

4. Bangladesh: In 1998, Bangladesh saw the worst flooding in recorded history: over 1000 people died, and 30 million were made homeless as floodwaters overtook everything. Two-thirds of the country was left underwater. It is estimated that, in the coming decades, the effects of climate change will force 20-40 million citizens in the South Asian country to become refugees.

5. Nepal (and Bhutan): Sitting in the shadow of Mount Everest, these two countries might come as more of a surprise; however, melting glaciers threaten the nations with severe flooding and eradication of agriculture, and neither country is well-equipped to deal with the implications of rising global temperatures, though they have adopted several measures in an attempt to combat climate change.

Worthy mentions: Marshall Islands, Vietnam, Kenya, Rwanda

This is only a small sampling of countries that would be affected. Along with the (relatively) simple issue of flooding come the more complicated ramifications of an increase in global temperatures, which would cause extreme weather patterns that would disrupt the normal flows of human activity around the world. UN Secretary-General Ban Ki-Moon has scheduled an international climate summit for September 2014 in New York City to address the growing urgency of global climate change.