Much of the carbon dioxide produced every year remains in the atmosphere and methane takes about 100 years to break down. The greenhouse gases in the atmosphere are building up more rapidly as we keep increasing the amount of fuel we burn.
If the air temperature is increasing, this can cause the temperature of the sea to increase. We know that the weather in different locations fluctuates each year. But we may be already witnessing signs of climate change. It takes less than a two degree rise in sea temperature for less than a week to start the coral bleaching process. The Great Barrier Reef in 1998 and 2002 had unusually high seawater temperatures that caused many reefs severe coral bleaching.
Most regions in the world with coral reefs are also showing major damage from coral bleaching. If temperatures continue to increase there is great concern for the health and future of coral reefs.
Some people still argue that current coral bleaching is due to natural fluctuations in sea temperature in the same way as weather changes from year to year. Even if this is correct, future climate change will still devastate coral reefs.