The Greens have welcomed the SA government's environmental water requirements study, which has been peer-reviewed by the Goyder Institute, to demonstrate what is needed to keep the Murray mouth open and ensure a healthy river system.

"We've always maintained that the protections the river needs must be based on scientific evidence," SA Greens senator and spokesperson for water and the Murray Darling Basin, Sarah Hanson-Young, said today.

There are more than 13 billion reasons why the climate package unveiled on Sunday is better at putting a price on pollution than its predecessor.

For starters, there's $10 billion for renewable energy projects. Unlike the Carbon Pollution Reduction Scheme (CPRS) proposed by the former Rudd government, this package lays the basis for science-based climate action.

South Australia will benefit from the historic climate action package which finally puts a price on carbon to cut pollution, the Australian Greens said today.

"The Greens went to the 2010 election promising to take action on climate change, and at last we have the results after many months of negotiations," SA Greens Senator, Sarah Hanson-Young, said.

The Australian Greens, the Labor government and the Independent MPs today announced an historic agreement on a climate action package that will put a $23 per tonne price on carbon pollution, as was first proposed by the Greens, support householders and invest billions of dollars in clean, renewable energy.

The Australian Greens are pleased the government has changed how it tries to determine the ages of minors charged with people smuggling offences because the previous outdated method caused unnecessary anguish to detained Indonesian boys and their families.

The Federal Opposition leader is being irresponsible in his claims that the OneSteel plant in Whyalla will close should a price on carbon pollution be introduced, the Greens said today.

"Mr Abbott is creating unnecessary anxiety among South Australians by claiming that putting a price on pollution will lead to OneSteel closing in Whyalla," South Australian Greens Senator, Sarah Hanson-Young, said.

"Just as he was plain wrong in claiming petrol prices would rise, he is wrong in talking up a One Steel closure.

Yesterday was a great day for the Greens. Our team in the Federal Parliament went from six to 10 with Governor-General Quentin Bryce presiding over the swearing-in of 12 senators from around the country who were elected in August last year.

The Australian Greens are calling on the federal government to alter the powers of the Foreign Investment Review Board to include water licences.

It comes amid an overwhelming response from everyday Australians toward the acquisition of prime farming land by foreign companies and shows the Federal government must act to ensure water allocation licences in the Murray Darling Basin and other part of the country are protected.

Sen. Sarah Hanson-Young and Senator-elect, Penny Wright, talk to the SA media on the SA Greens' numbers doubling in the Senate from July 1 as part of the Greens holding the balance of power in the new senate.

Tens of thousands of people attended peaceful rallies around the country on Sunday in support of action on climate change, despite the Coalition and News Ltd media empire's negative campaign against cutting pollution via a carbon tax.

I am writing this from Christmas Island and could not attend the rally in Adelaide. I am gladdened Australians were not intimidated from speaking out.

The Sunday before the rallies, the News Ltd press attacked proponents of taking action, such as actress Cate Blanchett, for publicly supporting efforts to combat climate change.