The federal opposition and industry groups are making a last-ditch push to raise concerns about the impact of climate laws on energy prices and jobs.
Changes to the safeguard mechanism will put a hard cap on emissions in a bid to reduce pollution. The nation's 215 biggest emitters will be forced to reduce their emissions by 4.9 per cent each year.
Labor has the support of the Greens and crossbenchers to secure the passage of the bill through the Senate by the end of this sitting week.
Liberal senator Jonno Duniam said it would only push big emitters overseas.
"We're part of this thing called the world," he said.
"If it's more expensive to do business here, like manufacture cement, aluminium or engage in native forestry, you are going to do it somewhere else where those countries don't care about the impact on the environment.
"No only are we offshoring emissions, but their jobs and the economic value of their communities."
The National Farmers' Federation says the impact of a turbocharged offsets market need to be considered.
Agriculture has been excluded from safeguard mechanism requirements.
"Offsets from farmland are the 'net' in the government's 'net zero' plan," NFF CEO Tony Mahar said.
"This will potentially escalate land use conflict, with pressure to turn food and fibre producing land into carbon sinks to counter the emissions from other industries."
Assistant Climate Change and Energy Minister Jenny McAllister said the legislation was a step closer to reaching net-zero carbon emissions by 2050.
Senator McAllister said the changes would reduce emissions by 205 million tonnes by 2030 - the equivalent of taking two-thirds of cars in Australia off the road.
The assistant minister added that the reforms ensured investment certainty required for the big emitters as the market works towards decarbonisation.
"What we seek to establish is not just the steps that will take up towards meeting the target," she said.
"But also the steps that will ensure our economy is geared up to take advantage of the economic opportunities that will come with it."
The government forced the upper house to sit all night on Tuesday and pushed debate late into Wednesday before it comes to a vote on Thursday.
Independent senator David Pocock said the legislation wasn't perfect, but it was a start.
Queensland Nationals senator Susan McDonald says the changes will choke energy supply and local jobs.
"These laws will most likely scuttle crucial gas projects, worsening the gas crisis, severely hampering our ability to balance the budget and denying people good-paying jobs in regional Australia," she said.
The opposition and One Nation have also expressed disdain at the process, calling it rushed after only receiving some of the amendments secured by the Greens minutes before debate.
One Nation leader Pauline Hanson attacked the legislation for impacting Future Fund earnings, with coal and gas stocks going down after the announcement.
The government disagreed with the proposition, saying the changes to the mechanism takes into account new entrants into the market and helps encourage companies invest in new, cleaner technology.
