其中一份研究來自國際再生能源總署（International Renewable Energy Agency, IRENA）。
不意外地，許多國家對《巴黎協定》主要的承諾內容，也就是國家自訂貢獻（Nationally Determined Contributions, NDC），都跟大幅推動再生能源的計畫相關。
再生能源裝設率發展到這樣的停滯不前，就算發電成本持平不降，都是非比尋常的情形。況且成本當然會變動，尤其是風能與太陽能。太陽能發電成本已在過去五年下跌約七成。風能設施原本就比太陽能便宜，所以數字沒那麼驚人，但根據國際能源總署（International Energy Agency, IEA）的報告，光去年一年內風能成本就降低了一成。
第二份研究來自「自然氣候解決方案」（Natural Climate Solution）的領域。基礎概念是將土地保持或回歸到吸收與儲存碳的狀態，包括盡可能讓土地達到自然的狀態，或是用可以留住碳的方式使用土地，例如不用深耕法，改採「最低耕作法」（minimum-till）務農。
主筆該研究的美國自然保育協會（The Nature Conservancy）推出了一套線上工具，可以看到全球各國若採行這些「自然方案」可達到的減碳潛力。
同時，據彭博新能源財經（Bloomberg New Energy Finance）最新的分析估計，英國在2026年前，超過一半以上的發電量可由再生能源供應。但是英國政府卻認為，2026年的十年後，再生能源發展還會在龜速爬行，僅能供應英國不到五成的電力。
At the Paris summit two years ago, governments made two separate promises on curbing the extent of climate change.
In one, they pledged to keep global warming since pre-industrial times ‘well below' 2 degrees Celsius, and to aim for 1.5ºC.
In the other, they put forward national plans on curbing carbon emissions that take us to a very different world – with global warming of around 3ºC by the end of the century.
That's why phrases such as ‘bend the curve' and ‘ramp up the ambition' are heard so often in the corridors and coffee bars of the UN convention centre here in Bonn.
The prevailing theory is – and it's a pretty obvious one – that many governments aren't yet convinced that they can cut emissions on the scale needed to usher in that ‘well below 2ºC' world without inflicting substantial pain on their economies. They like the vision, but not yet the pathway needed to get there.
But two recent pieces of research suggests there's another answer that may be just as important: they haven't looked hard enough at what's happening in their own countries, at what they've promised in other fora, or at what's possible.
Good knight IRENA
One comes from IRENA, the International Renewable Energy Agency.
Unsurprisingly, plans for a big rollout of renewable energy form a centrepiece of many countries' pledges into the Paris Agreement, which are known as Nationally Determined Contributions (NDCs).
IRENA boffins simply went through countries' NDCs to see what they're proposing for renewables.
Here's the headline figure. Totting up the renewable energy rollout plans contained in the NDCs adds up to a projected increase in renewable energy capacity of 3.6% per year between 2015 and 2030.
Sounds ambitious? Well – not when the annual growth rate seen 2010-2015 was 8.1%.
Even if prices were constant it would be extraordinary to see the deployment rate grinding to a halt like this – and of course, prices aren't constant, certainly not for wind and solar. Solar prices have fallen by about 70% in the last five years. The figure for wind is less spectacular as it was already cheaper than solar – but the International Energy Agency reports a price drop of 10% over the last year.
And, as you'd expect, that same IEA report showed that the installation rate of renewables is increased, by 8% in a year, rather than decreasing.
That suggests that overall, the NDCs vastly underestimate the amount of renewable energy capacity that will be installed over the years to 2030.
IRENA also found that some countries are forecasting less ambition in their NDCs than they are in their national development plans.
Across Africa, NDCs project an expansion of 40 gigawatts (GW) in renewable capacity by 2030. But national development plans show Africa can expect 110 GW at least.
So, simply by reflecting their national plans more accurately in their NDCs, many countries would be able to forecast more ambitious emission curbs than they have yet put forward. And the ambition would grow still further if countries reflected what's economically likely.
The second bit of research comes in the field that's becoming known as ‘natural climate solutions'. Here, the basic idea is to keep land in, or return it to, a condition in which it absorbs and stores carbon. Which in some cases means attaining as natural a state as possible, and in others means using land in ways that retain carbon, for example doing ‘minimum till' farming rather than deep ploughing.
There are obvious trade-offs here with other demands for land on an increasingly crowded planet, but seeing as many of these approaches bring benefits for wildlife or people if they're done well, there are obvious attractions too.
A couple of months back we saw a major scientific paper totting up the potential contribution of natural climate solutions to achieving the Paris climate target. The conclusion: they can get us about one-third of the way there at reasonable cost.
Now, The Nature Conservancy, the US-based conservation charity which led that scientific paper, has released a cool online tool that allows you to see, for every country in the world, what potential exists for meeting NDC targets through these ‘natural solutions'.
For some, it's pretty big: Indonesia can achieve more than its entire NDC pledge through cost-effective natural solutions alone.
Now, such a tool can only be as good as the data going into it. And one suspects that the numbers in and therefore the conclusions out are going to change over time.
Nevertheless, it illustrates that some countries may be able to increase their NDC pledges without too much bother – although in some cases (Indonesia still being a good example) they're likely to need the financial support they've been promised since 2009 in order to realise the full potential.
And at home?
Even countries such as the UK, which are more sophisticated than most in their climate change plans, may be under-estimating the potential of both natural climate solutions and renewables to cut emissions.
The Nature Conservancy's tool estimates that afforestation and other land-use changes could bring about one-sixth of the emission cut pledged in our NDC (which, just to be clear, is currently the EU's NDC as the bloc made a joint pledge). It's not clear – genuinely not clear from published plans, I'm not having a dig – whether the government has factored this in or not.
Meanwhile the latest analysis from Bloomberg New Energy Finance reckons that renewables could provide more than half our electricity by 2026. By contrast, the government thinks [pdf link] that a decade after that, renewables will still be chugging along at under half.
Now, all of this doesn't mean that if countries re-calculate their NDCs thoroughly, we'll magically be on target for the 'well below 2ºC' world of the Paris Agreement. Almost certainly that's not the case.
But it does suggest there's more potential there than many governments realise, in these two areas and maybe in others, to become bolder – and so take us closer to the world they said in Paris that they want.