Human induced climate change threatens coastal and marine ecosystems through sea-level rise, acidification, and changes in weather patterns and water temperatures. These changes will also seriously alter coastal development, the reliability of ocean shipping, coastal recreation and marine activities such as oil platforms and aquaculture, thus adding economic risks.

Oceans and climate are inextricably linked and oceans play a fundamental role in mitigating climate change by serving as a major heat and carbon sink. Oceans also bear the brunt of climate change, as evidenced by growing acidification, sea level increase, and changes in temperature and currents, all of which in turn impact the health of marine species, ecosystems, and our coastal communities. As concerns about climate change increase, the interrelationship between oceans and climate change must by recognized, understood, and incorporated into climate change policies.

Our oceans are especially vulnerable to the adverse impacts from human emissions of greenhouse gases. These impacts, which are already being experienced, include: air and water temperature changes, seasonal shifts, ocean acidification, coral bleaching, sea level rise, coastal inundation, coastal erosion, dead zones, new diseases, loss of marine mammals, changes in levels of precipitation, and fishery declines.  In addition we can expect more extreme weather events (droughts, floods, storm surges) both in intensity and frequency.  To protect our valuable marine ecosystems, coastal aesthetics and coastal communities, we must act.

"Human beings are now carrying out a large-scale geophysical experiment of a kind that could not have happened in the past nor be reproduced in the future. Within a few centuries we are returning to the atmosphere and oceans the concentrated organic carbon stored in sedimentary rocks over hundreds of millions of years.  This experiment, if adequately documented, may yield a far-reaching insight into the processes determining weather and climate."
[Roger Revelle & Hans Suess, Carbon dioxide exchange between the atmosphere and ocean and the question of an increase in atmospheric CO2 during the past decades, Tellus, 9, p  19-20, 1957]
Since the Industrial Revolution, mankind has increased the acidity of our oceans by 30% and has increased the amount of carbon dioxide in our atmosphere by over 35%, primarily from the burning of fossil fuels. Other human activities have resulted in additional major contributions of greenhouse gases, such as methane and nitrous oxides. Added together, our oceans and we now face "unequivocal" warming of our climate, and an ocean with an altered pH.

Scientists, indigenous peoples, fishers, and others for years have been observing and documenting, often with alarm, substantial changes that are occurring as a result of climate change. Concerns are compounded by the fact that climate change is also making new marine ecosystem threats and challenges possible, such as Arctic shipping routes and new off-shore oil and gas leasing.

In all its potential forms, climate change is having and will, if unaddressed, continue to have even a more dramatic effect on the oceans now and into the future. The positive news is that there are critical adaptation measures that can be taken to reduce the impacts; and we also have greenhouse gas reduction solutions. Oceans may have a significant role in some of these renewable energy solutions. Notably, under any circumstance, it is critical that the public and our decision makers understand the impacts and costs of global warming on our oceans and coastal communities.

Global warming is having and will continue to have significant negative effects on our oceans and the communities that depend on them. The loss of ice sheets in the arctic is having and will increasingly have adverse consequences for many species of marine mammals like polar bears, walruses, and ice seals. Warmer oceanic and riparian waters is resulting in increased marine diseases and invasive species, changes in weather systems, modifications in species distribution patterns, dead zones and coral bleaching. Larger and more frequent storms are accelerating shoreline erosion, loss of community infrastructure, increased fishing risks and adverse health consequences. Ocean acidification will harm calcium carbonate plankton, adversely affect shellfish larvae, hinder the ability of corals to build new reefs and cause serious food chain disruptions. Sea level rise will cause habitat loss from inundation, infrastructure damage, and climate refugees that will need to be relocated as their island and coastal homelands are eliminated.

The overall solution to climate change is to significantly reduce the emission of greenhouse gases. This will require action at international, national, local and community levels, around the world.

Simultaneously, it is important to the health of the oceans—and us—that additional threats are avoided, and that our marine ecosystems are managed thoughtfully in light of the change that has occurred and is predicted to occur. It is also clear that by reducing the immediate stresses of excess human activities, we can increase the resilience of ocean species and ecosystems to long-term change. In this way, we can invest in ocean health and its "immune system" by eliminating or reducing the myriad of smaller ills from which it suffers.
Climate Change Expertise at The Ocean Foundation

Gramling, C. "How warming oceans unleashed an ice stream." Science. 13 Niovember 2015: 350 (6262), 728.
This brief article describes a Greenland glacier that is shedding kilometers of ice into the sea each year as warm ocean waters undermine it. What is going on under the ice raises the most concern, as warm ocean waters have eroded the glacier far enough to detach it from the sill, which will allow it to retreat even fast and also creates huge alarm about the potential sea level rise.

Hoegh-Guldberg, O., et al. ISRS Consensus Statement on Coral Bleaching & Climate Change. December 2015.
Coral reefs provide goods and services worth at least US$30 billion per year and support at least 500 million people worldwide.  Due to climate change, reefs are under serious threat if actions to curb carbon emissions globally are not taken immediately.  This statement was released in parallel with the Paris Climate Change Conference in December 2015.

The Institute for Sustainable Development and International Relations. Climate - Oceans and Coastal Zones: Policy Brief, September 2015.
This policy brief outlines the intertwined nature of the ocean and climate change, calling for immediate CO2 emission reductions. It explains the significance of these climate changes in the ocean. It is based on a scientific paper recently published in Science (Gattuso et al., 2015), which synthesizes recent and future changes to the ocean and its ecosystems, as well as to the goods and services they provide to humans. 

Levin, L. and N. Le Bris. "The deep ocean under climate change." Science. 13 November 2015: 350 (6262), 766-768.
Despite huge ecosystem services of the deep ocean, it is often overlooked in the realm of climate change and mitigation.  The water 200 meters and below absorbs vast amounts of carbon dioxide and needs specific attention and increased research to protect its integrity and value.

Spalding, M. and B. Brown. "Warm-water coral reefs and climate change." Science. 13 November 2015: 350 (6262),  769-771.
This journal article is a very helpful overview of the impacts of climate change on coral reefs.  Coral reefs support huge marine life systems as well as providing critical ecosystem services for

Stocker, T. "The silent services of the world ocean." Science. 13 November 2015: 350 (6262), 764-765.
The ocean provides crucial services to the earth and to humans that are of global significance, all of which come with an increasing price caused by human activities and increased carbon emissions. The author emphasizes that this needs to be taken into account when considering adaptation to and mitigation of anthropogenic climate change, especially by intergovernmental organizations who claim to do so.