Human activities are one of the main causes of climate change. Such activities are affecting the oceans on a global scale and those changes are disrupting ecosystems and food webs. It is clear that ocean resources provide many benefits for mankind, but it is also clear that it is globally important to address the issues that are contributing to climate change overall.
The effects of global climate change are evident all over the world: we see it in the diminishing sea ice in the Arctic, in New England’s low-lying coastal areas and in the collapse of the sea floor in the Great Barrier Reef. Carbon dioxide levels are rising and so are sea levels. A mass migration shift is taking place, with animals and plants disappearing from some areas and appearing in others. Researchers believe that oceans are a leading indicator of climate change; through studying changes in the ocean, we can better understand the causes and effects of a changing climate.
The oceans are taking the brunt of warming in the climate system. This will cause direct physical and biogeochemical impacts. The impacts expected by 2050 include: reduced seasonal ice zones, which means the disappearance of Arctic summer sea ice; increasing stratification of ocean layers, leading to oxygen depletion and decreased nutrient cycling; increased venting of the GHG methane from the Arctic seabed; and increased incidence of anoxic and hypoxic events.
The IPCC’s Fifth Assessment Report (AR5) was released recently and it outlines ways to address global climate change. Sustainable development and equity provide a basis for assessing climate policies and highlight the need for addressing the risks of climate change overall. It is important today to begin limiting the effects of climate change in order to achieve sustainable development and equity, including poverty eradication.
Climate change requires a collective action on a global scale, because most greenhouse gases (GHGs) accumulate over time and mix globally – and emissions by any agent, individual, community, company or country affects the planet as a whole.
The IPCC has determined that international cooperation is required to effectively mitigate GHG emissions and address other aspects of climate change. Countries’ past and future contributions to GHG accumulation in the atmosphere are different, and many countries face varying challenges in terms of addressing mitigation and adaptation.