The overall temperature of the ocean has been increasing. This increase in ocean temperature is attributed to the phenomenon of global warming, primarily caused by human activities such as the burning of fossil fuels and deforestation, which release greenhouse gases into the atmosphere. These greenhouse gases trap heat and contribute to the warming of the Earth's surface, including the oceans.
Regarding the rate at which ocean temperature is changing, it is generally observed that the rate has increased over recent decades. This acceleration in the rate of ocean warming is a result of the cumulative impact of human-induced climate change. The Intergovernmental Panel on Climate Change (IPCC) has reported that the rate of ocean warming has been on the rise and is expected to continue increasing in the future.
Multiple factors contribute to the increased rate of ocean temperature change. These include the increasing concentration of greenhouse gases, reduced heat absorption by melting ice, changes in ocean circulation patterns, and the slow response of the ocean to temperature changes due to its large thermal inertia. Additionally, feedback mechanisms within the climate system can amplify the rate of temperature change, further contributing to the accelerated warming of the oceans.
It's important to note that the ongoing monitoring and research on ocean temperature changes are crucial to obtaining a comprehensive understanding of the long-term trends and potential variations in the rate of change.