April 23 (Reuters) - Countries are under pressure to

make progress on a first-ever global plastics treaty this week,

but they face tense negotiations in the Canadian capital with

parties deeply divided over what the treaty should include as

talks begin on Tuesday.

If governments can agree on a legally binding treaty that

addresses not just how plastics are discarded, but also how much

plastic is produced and how it is used, the treaty could become

the most significant pact to address global climate-warming

emissions since the 2015 Paris Agreement.

The production of plastics accounts for some 5% of climate

emissions and could grow to 20% by 2050 unless limited,

according to a report last week from the U.S. federal Lawrence

Berkeley National Laboratory.

When countries agreed in 2022 to negotiate a legally binding

treaty by the end of this year, they called for addressing the

full lifecycle of plastics - from production and use to waste.

But as negotiations kick off in Ottawa, there is staunch

opposition from the petrochemical lobby and some governments

dependent on fossil fuels to limiting production or banning

certain chemicals.

Thousands of delegates, including negotiators, lobbyists and

non-profit observers, were expected at the Ottawa summit, the

fourth negotiating round ahead of a final agreement due in

December - making this one of the fastest U.N.-led treaty

efforts to date.

They were greeted by protesters staging a "die-in" - laying

down and pretending they are dead - on Tuesday morning across

from the negotiations' venue.

"This process is without doubt an accelerated and ambitious

one, because we don't have decades to act," said Inger Andersen,

executive director of the United Nations Environment Programme.

DEEP DIVISIONS

The chair of the Ottawa negotiations told Reuters he planned

to split national delegates into seven working groups this week

to work on unresolved issues, including what the treaty should

include and how it should be implemented.

"Time is not our best ally," said summit chair Luis Vayas

Valdivieso, who is also Ecuador's vice minister of foreign

affairs.

Steven Guilbeault, Canada's environment minister, told the

opening plenary: "We now need to narrow down the options,

identify where there is growing consensus and make real progress

on the agreement," adding that the pact should establish targets

and eliminate unnecessary single-use plastics and chemicals.

During the last treaty talks in November in Nairobi, there

was strong support from 130 governments for requiring companies

to disclose how much plastic they produce, and which chemicals

they use in the process.

With plastics production on track to triple by 2060,

supporters say such disclosures are a basic first step in

controlling harmful plastic waste - the vast majority of which

ends up as trash marring landscapes, clogging waterways or in

landfill - and harming public health.

Almost a fifth of the world's plastic waste is burned, which

releases high amounts of carbon emissions. Less than 10% of it

is recycled, according to U.N. data.

However, a handful of fossil fuel-dependent nations calling

themselves the "Like-Minded Countries" have argued against

limiting production or banning certain chemicals. The group,

which includes Saudi Arabia, Russia and China, says the treaty

should focus only on tracking plastic waste.

The position is shared by the petrochemical industry.

"We are looking at the agreement to accelerate actions that

industry is already doing on its own," such as boosting

recycling and redesigning plastic products, said Stewart Harris,

a spokesperson for the International Council of Chemical

Associations.

Saudi officials declined to comment. The state-owned oil

company Saudi Aramco has said it plans by 2030 to be sending

nearly one-third of its produced oil to petrochemical plants to

make plastics.

China, which produces roughly a third of the world's

plastic, "has always attached great importance to the control of

plastic pollution and is willing to work with other countries to

make joint progress in negotiations," Chinese foreign ministry

spokesperson Lin Jian said.

In the opening session, key regional blocs outlined some key

elements they want to see in a treaty.

The Asia Pacific group said that countries should

receive financial and technical assistance for waste management

infrastructure as they take on new obligations under the

agreement.

The Africa group called for the creation of a new

multilateral fund to help developing countries meet new

obligations under a treaty and called attention to the fact that

the continent has become a target for illegal trade of plastic

waste and urged negotiators to prioritize "waste prevention and

reduction before non-toxic waste recycling and disposals."

ARGUING FOR AMBITION

It is unclear whether the majority of countries asking for

production limits can persuade the holdouts to support such a

measure. Environmental groups and scientists say production

limits are essential.

"More plastic production means more plastic pollution," said

Bjorn Beeler, international coordinator of the International

Pollutants Elimination Network.

That point was underscored in a letter published on Tuesday

by 30 scientists comprising the Scientists Coalition, who have

told negotiators that caps on plastic production are the only

way to tackle the problem and called on industry to provide

detailed figures for production and disclose the chemicals they

use to enable more efficient recycling of components.

The biggest generator of plastic waste, the U.S., has

refrained from joining the negotiating blocs. Measures proposed

by U.S. negotiators include requiring countries to tackle

certain chemicals that have raised public health concerns as

well as "single use" plastic products that are deemed wasteful.

A State Department official told Reuters the U.S. delegation

wanted the treaty to be ambitious in its goals - but to let

governments decide how they would reach those goals, similar to

the structure of the Paris Climate Agreement.

More than 60 countries making up the so-called High-Ambition

Coalition, including European Union members, Mexico, Australia,

Japan and Rwanda - and most recently Ukraine, are also arguing

for a strong treaty that tackles production and requires

transparency and controls for chemicals used in the process.

But unlike the U.S., they argue the treaty must impose

global measures and targets rather than a system of national

action plans.

Some Democratic U.S. lawmakers, including a delegation

attending the opening of the negotiations, called on the U.S. to

join the coalition and support stricter measures, even if

Congress will not ratify the treaty.

"The Paris model is a wishing well strategy where you

hope that just having conversations will take us down a path of

reducing plastic pollution," Oregon Senator Jeff Merkley told

Reuters. "A treaty should include binding obligations and

constraints."