By Roger Harrabin
Environment analyst, BBC News
Coral offers researchers an insight into the effects of ocean acidification
The UK government has launched an £11m ($16m) five-year research programme into ocean acidification.
Researchers say seas are becoming more acidic as a result of CO2 from human activities being absorbed by seawater, which alters the oceans' chemistry.
Ministers say acidification of the oceans will be one of the major environmental concerns of this century.
The study will focus on the Atlantic, Antarctic and Arctic oceans and assess how marine ecosystems are affected.
The programme, co-funded by the Department for Environment, Food and Rural Affairs (Defra) and the Natural Environment Research Council (Nerc), will also examine the implications for people and the economy.
Up to 50% of the CO2 released by burning fossil fuels over the past 200 years has been absorbed by world's oceans
This has lowered the pH value of seawater - the measure of acidity and alkalinity - by 0.1
The vast majority of liquids lie between pH 0 (very acidic) and pH 14 (very alkaline); 7 is neutral
Seawater is mildly alkaline with a "natural" pH of about 8.2
The IPCC forecasts that ocean pH will fall by "between 0.14 and 0.35 units over the 21st Century, adding to the present decrease of 0.1 units since pre-industrial times"
"Ocean acidification will be one of the biggest environmental concerns of this century, with major and far-reaching impacts," said Nature and Marine Environment Minister Huw Irranca-Davies.
"We need to understand much more about the scale and nature of the effect CO2 is having on our oceans and marine life."
Scientists say ocean acidity has increased 30% since the Industrial Revolution, the fastest change in ocean chemistry for at least 65 million years.
Researchers warn that it could result in a massive extinction of life in the seas.
Creatures that form alkaline shells are likely to be particularly affected and coral reefs may begin to crumble before the end of the century.
The problem has only recently hit the headlines, so research is still in its infancy.
US scientists are among the leaders in this new field, and the Obama administration says it is very concerned about acidification.
The nation's Congress has also recently approved funds for a major research programme.