The Footsie opened up higher but fell into the red in early trading as two giants weighed up the effects of an Australian climate change proposal.International Power opened strongly to lead the risers after responding to the proposed climate change plan in Australia. Under the proposed plan to reduce CO2 emissions by 2020 to 5% below 200, "brown-coal fired power generation will be eligible for carbon credits for the first five years starting July 2012, with a one off cash payment for the first year followed by annual credits until 30 June 2017," the firm said.Mining giant Rio Tinto, however, has opened lower after voicing its disappointment over Australia's carbon tax proposal of A$23 a tonne on the 500 heaviest emitters as of 1 July 2012, joining the sector's warning that the plan would hinder investment and jobs growth in the nation's mining industry.Hong Kong infrastructure group Cheung Kong has made a non-binding indicative proposal to bid for UK water and waste management group Northumbrian Water, offering 465p cash per share plus the right to retain the recently declared net final dividend of 9.57p. Northumbrian rose higher in early trading.Permanent placings are driving growth at international recruitment firm Michael Page though the temps market is also on the up, meaning second quarter gross profit was ahead of management expectations. Egypt-focused gold miner Centamin Egypt was in the red after making a £7.48m offer for PLUS-quoted miner Sheba Exploration.Managed services provider Redstone was firmer after it said it almost halved full year pre-tax losses as it continues with its restructuring programme.BCFTSE 100 - RisersInternational Power (IPR) 309.60p +2.75%Essar Energy (ESSR) 401.70p +0.96%Tullow Oil (TLW) 1,315.00p +0.92%Severn Trent (SVT) 1,511.00p +0.80%Cairn Energy (CNE) 407.50p +0.77%Carnival (CCL) 2,360.00p +0.73%Scottish & Southern Energy (SSE) 1,423.00p +0.71%Centrica (CNA) 329.80p +0.70%Capita Group (CPI) 710.50p +0.64%Fresnillo (FRES) 1,433.00p +0.63%FTSE 100 - FallersBritish Sky Broadcasting Group (BSY) 699.00p -6.80%Royal Bank of Scotland Group (RBS) 36.66p -1.48%Barclays (BARC) 239.85p -1.40%GKN (GKN) 237.20p -1.21%Lloyds Banking Group (LLOY) 46.10p -0.99%Prudential (PRU) 726.00p -0.89%Legal & General Group (LGEN) 122.20p -0.81%Aviva (AV.) 432.30p -0.80%Man Group (EMG) 257.70p -0.73%Resolution Ltd. (RSL) 290.20p -0.72%