The surprise agreement was the result of 30 meetings between state climate envoys, and commits both states to achieving the 1.5-degree global warming target set out in the Paris Agreement. It outlines the importance of the transition to green energy, and enhanced collaboration on climate technology innovation.

In March, I wrote for the Lowy Institute's The Interpreter that a bilateral US-China agreement on climate change was unlikely. The piece was written after tense talks between the US and China at the Alaska Summit, which did not mention climate change. In Alaska, the US emphasised its concerns over human rights in China. I outlined a key tension in Biden's foreign policy - putting pressure on China for its human rights abuses while co-operating with it on broader issues. This tension was emphasised in January when US special climate envoy John Kerry stated collaboration with China on climate change would "never be traded" for calling out China's human rights abuses.

Maybe it was my Millennial distrust of states acting for the greater good on climate change, or the result of worsening relations over 2020 - but I am pleased to be proven wrong. The US and China have agreed to increased climate co-operation during this decade.

While the declaration is nothing new in terms of global climate action - it remains vague and merely acts to support agreements from COP26 - we should at least welcome it as a signifier of improved US-China relations. Both governments appear to be separating their broader geostrategic competition from their climate commitments.

The climate declaration was managed by the special climate envoys of both states, John Kerry and Xie Zhenhua. Biden's pick of Kerry as a special climate envoy is significant for US-China relations, given Xie and Kerry's two-decade-long working relationship.

This is not the first climate agreement Xie and Kerry have brokered. In 2014, a year before COP21 in Paris, the US and China agreed to a more comprehensive climate deal.

Earlier during COP26, Biden criticised Xi for not attending in-person at Glasgow. The strong relationship between Kerry and Xie is instead at the heart of the two countries' commitment to climate co-operation.

But while it is important we welcome a positive, if underwhelming, step on climate, the same tension remains between Biden's intention to pressure China on human rights and co-operate on climate change.

Many questions remain as to what the document means for the US's commitment to pressuring China on human rights, and the future of US-China competition more broadly. A transition to a green economy must be just, fair and free from forced labour.

Take polysilicon, a material key to solar panel manufacturing and supply chains. 65 per cent of the world's polysilicon is produced in Xinjiang, 80 per cent in China. Polysilicon is produced in Xinjiang because its manufacturing consumes a lot of energy, and Xinjiang is home to some of China's cheapest coal.

In April, a report by Bloomberg uncovered that the owners of three of Xinjiang's polysilicon factories are linked to employment programs associated with allegedly forced labour in Xinjiang. When visiting these factories, armed guards are on the grounds. If this were a typical polysilicon refinery, there would be absolutely no need for them.

As global demand for solar panels and other materials required to source renewable energy increases, we must pressure governments and companies to ensure their supply chains are free from forced labour and have strong working conditions. Human rights and labour laws cannot be left out of our transition to a green economy.

Xie has warned the US that "climate co-operation cannot be separated from the wider environment". He's right - it's easier said than done. Whilst climate change might transcend US-China competition, it does not transcend human rights.

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The US must ensure that its enhanced collaboration with China on climate change, as laid out in the Glasgow Declaration, is not linked to forced labour. The US's Magnitsky laws, which sanction foreign individuals linked to human rights abuses, will be assessed as climate co-operation expands. This year, the US has sanctioned and restricted exports of three Chinese manufacturers of solar panels, for their involvement with forced labour in Xinjiang.

In the same way nuclear proliferation provided a common ground for the US and USSR to meet during the Cold War - both states took the threat of a nuclear catastrophe seriously, albeit while still building up their own nuclear capabilities - maybe climate change will be the issue that brings together a competing US and China.

Kevin Rudd says the agreement is "not a gamechanger", but is important in the broader context for US-China geopolitics.

Part of the reason I questioned the possibility for US-China climate co-operation earlier in the year was because geopolitical tensions between the US and China were not improving under Biden. Biden's policy has not swayed too far from Trump's when it comes to China. But where Biden differs is his centralisation of climate change in America's foreign policy.

The Glasgow Declaration is a win for diplomacy and improved US-China relations - however it is still to be determined whether it's a win for climate change. The declaration is likely to add some energy into an otherwise lacklustre COP26.

Co-operation between the world's two largest economies and emitters is vital to ensure we remain below 2 degrees warming. However, we must demand better agreements from states, more specific targets and ensure that our transition to green energy is just and humane.