CANBERRA, AUSTRALIA -- Australia's new government on Monday blamed the previous administration's inaction on climate change for an increase in the nation's greenhouse gas emissions last year.

Australia emitted 488 million metric tons (538 million U.S. tons) of carbon dioxide and equivalent gases in the last calendar year, up 0.8%, or 4.1 million metric tons (4.5 million U.S. tons), from 2020, according to the government's National Greenhouse Gas Inventory update for the .

Factors that caused the increase included a 4% rise in transport emissions as pandemic travel restrictions eased and 4.2% more agricultural emissions as rain ended years of drought across large swathes of southeast Australia.

Climate Change Minister Chris Bowen, whose centre-left Labor Party came to power at elections last month, accused the previous conservative coalition of relying on COVID-19 and drought to achieve emission reductions toward the end of its nine years in power.

"With the resumption of more normal economic activity, continuing recovery from drought and increases in manufacturing and resources sector activity, the previous government caps off its record of denial and delay by increasing emissions on the way out," Bowen said in a statement.

Labor was elected on a promise to reduce Australia's emissions by 43% below 2005 levels by 2030.

The former government had a less ambitious target of a 26% to 28% cut by the end of the decade.

Some minor parties and independent lawmakers are calling for stronger action to limit global warming to less than 2 C (3.6 F).

By the end of last year, Australia had achieved a 21.4% reduction, according to the latest data released Monday.

Opposition spokesperson on climate change Ted O'Brien said Australia's emissions were now lower than any time when Labor was last in government from 2007 until 2013.

O'Brien challenged the new government to deliver cheaper power and to beat its target while delivering economic growth.

Tim Baxter, a senior researcher at the Climate Council think tank, expected Australia's emissions to rise further this year before the new government's more effective policies showed results.

"It takes a little while for these sorts of policies to flow through," Baxter said. "They could be stronger, but the Labor Party has some measures that will start bending the curve."

The council is an independently funded non-profit that replaced the Climate Commission, a publicly funded agency abolished in 2013 by the previous government.

The council recommends Australia reduce emissions by 75% by 2030 and achieve net zero by 2035. The government's net-zero target is 2050.

News of Australia's increasing greenhouse gas emissions comes as climate activist group Blockade Australia kicked off a weeklong campaign of disruption in Sydney by shutting down the downtown Sydney Harbor Tunnel during Monday morning's peak traffic period.

Traffic had to be rerouted across the Sydney Harbor Bridge for about an hour.

Police arrested 11 demonstrators including a woman who parked her car across the tunnel's south-bound lanes then attached her neck to the steering wheel with a lock and chain, officials said.

New South Wales state Assistant Police Commissioner Paul Dunstan condemned the actions of some of the 50 to 60 demonstrators.

"The behaviour of this group was nothing short of criminal activity," Dunstan said.

"The throwing of bicycles, the throwing of garbage bins, the throwing of other items in the path of police, in the path of media, in the path of innocent members of the public just walking by, will not be tolerated and cannot be by the people of New South Wales," he added.

Blockade Australia protest organizer Sally-Ann Brown said the disruption was necessary because policymakers were not listening.

"I got the feeling today that the public were not upset, the police were upset," Brown said.