The second week of the COP26 climate summit in Glasgow, Scotland, has begun -- and things are starting to heat up. 

Here's what to know. 

What a 'Glasgow Agreement' might look like 

The UK's COP26 presidency released something that is called, quite oddly, a "non-paper," which is basically a list of things that could end up in the final Glasgow agreement. 

So what's in it? 

• There are references to strengthening language around limiting global warming to 1.5 degrees above pre-industrial levels, which was COP26 President Alok Sharma's big goal for the summit. The 2015 Paris Agreement obliged countries to try and limit warming to 2 degrees, and preferably closer to 1.5 degrees. But more recent science shows that the world really does need to limit warming to 1.5 degrees to avoid catastrophic climate change. 
• There's reference to the need to "accelerate" cuts to greenhouse gas emissions rapidly over this decade. This is in response to concerns that many countries have made net-zero commitments for mid-century, but have either no plan on how to get there, or plans that are too weak to actually meet the targets. 
• There's an acknowledgment that more money needs to be transferred from the developed world to the Global South to help those countries adapt to the climate crisis. This is emerging as one of the biggest sticking points in the conference. The document has a number of "placeholder" points, showing that several requests are proving contentious. 

Greenpeace called the list "exceptionally weak" and criticized it for not mentioning fossil fuels, the main driver of climate change. 

Major fossil fuel producers resist 1.5 degrees 

Environmental groups say Saudi Arabia, China and Russia are resisting the effort to adopt a stronger goal. 

Several parties to the Paris Agreement, including the US, UK and EU, want the goal to shift to 1.5 degrees. But Jennifer Tollman, a senior policy advisor for climate think tank E3G, said some major fossil fuel producers are showing skepticism about formalizing that target. 

"We'll have to see who goes public in their positions, but those that have definitely shown skepticism include Saudi Arabia," Tollman told CNN, adding that China and Russia were also showing some resistance. 

On Monday, E3G sent a briefing note to media that said Saudi Arabia was "hinting at using stalling tactics on the adaptation items to avoid ambitious decisions" about lowering the temperature target. 

Greenpeace International Executive Director Jennifer Morgan said Saudi negotiators on Friday night moved to block negotiations on what's known as a "cover decision" -- the umbrella message that summarizes what an agreement means. It's typically the strongest language in an agreement. 

A Dutch lawmaker from the European Parliament, Bas Eickhout, also said that China was being "difficult" and was not being particularly vocal on its stance on any of the key issues, except for its opposition to formalizing 1.5 degrees. 

"China is not being very forthcoming on almost everything," Eickhout said. "Everyone is trying to understand what China is ready to do." 

CNN has reached out to Saudi, Chinese and Russian officials for comment. 

Obama swipes at Trump, China, Russia 

The Biden administration's COP26 firepower didn't stop after the US president left Scotland. On Monday, former President Barack Obama took the stage to declare "the US is back" on climate. 

As expected, Obama took a swipe at former President Donald Trump for "four years of active hostility towards climate science," and pulling the US out of the Paris Agreement, which Obama played a lead role in negotiating. 

He also criticized Chinese President Xi Jinping and Russian President Vladimir Putin for skipping the COP26 entirely. He called that decision "particularly discouraging," adding "their national plans reflect what appears to be a dangerous absence of urgency, a willingness to maintain the status quo, on the part of both those countries." 

Obama talked up President Joe Biden's big commitments on climate and decarbonization, but he tempered expectations about just how ambitious the US can be on climate, reminding the audience that Biden is limited by politics in Congress, as Obama was. 

"Keep in mind, Joe Biden wants to do even more," Obama said. "He's constrained by the absence of a robust majority that's needed to make that happen. Both of us have been constrained in large part by the fact that one of our two major parties has decided not only to sit on the sidelines, but express active hostility toward climate science, and make climate change a partisan issue." 

Obama nodded to the fact that while Biden scored one big legislative victory with his infrastructure bill passing last week, the president's massive climate and economic bill is still unfinished. Congress, and the moderates in Democrats' slim majority, have massive say over Biden's climate policy. 

More wrangling on who should pay what 

The developed world agreed more than 10 years ago that by 2020, it would transfer $100 billion a year to countries in the Global South to lower their emissions and adapt to climate change. 

But there is another ask from many developing countries: to be compensated for the damage the crisis has already wreaked in the form of climate reparations. 

Underpinning this idea is that wealthy countries are more responsible, historically, for climate change. Some countries on the frontlines of the crisis feel nations that have polluted the most should be held liable. 

Mohamed Adow, director of the think tank Power Shift Africa, said: "The US administration, including the current one, has been doing everything to block any climate... loss and finance discussion." 

"So they will be happy to talk about the importance of loss and damage, and the need to provide support to some of the climate-vulnerable countries who are already suffering some of the worst of climate change, without any inclusion of loss and damage finance. And so this is just to try and avoid any liability and any requirement to provide compensation." 

The US State Department declined to comment about negotiations around liability for the climate crisis. 

US Pacific Islander introduces the former president 

Sheila Babauta, a member of the Northern Mariana Islands House of Representatives, took the stage at COP26 to introduce Obama and speak about the issues that her home islands face. 

The US mainland has faced worsening hurricanes and storm surge in the Gulf Coast, while the West battles a historic drought and raging wildfires. But it's worth noting that the climate crisis also poses a threat to Americans in US territories in the Pacific Ocean. 

"As the first stewards of the land and ocean, our traditional knowledge can guide the way," Babauta said in her speech. "All together we hold the keys to solving the issues of militarization, climate change and climate colonialism. We are not passive victims. I am here to amplify the voices of those who live on the frontlines." 

Wearing islander regalia — a flower crown and a lei — Babauta, who is Indigenous Chamorro from the island of Saipan in the Northern Mariana Islands, spoke of the worsening storms, disappearing shorelines and rampant militarization that plague the islands. 

The Northern Mariana Islands — Saipan, Tinian, and Rota — are tiny dots on the map in the middle of the Pacific, but played a pivotal role in World War II. The islands became a US territory in 1975 and, along with the neighboring island of Guam, have turned into a hub for the US military, which has contributed to greenhouse gas emissions, ocean pollution and environmental degradation. 

- by Angela Dewan, Amy Cassidy, Ella Nilsen and Rachel Ramirez, CNN