I write this with a heavy heart, because I really love meat. And dairy. But unfortunately the evidence suggests they are really quite bad for the planet.
I argued last week that perhaps flying isn't as awful for the world as it is made out to be. I can't make quite the same case for these foods groups, even though I was selfishly hoping to find an obvious set of flaws in the conventional wisdom.
The figures are too jaw-dropping for that.
According to a comprehensive 2018 study by Oxford University scientists, meat and dairy provide 18% of calories to the global population, but use 83% of all farmland.
A quarter of all global greenhouse gas emissions comes from food production and forestry. And almost 60% of those food emissions come from animal products.
There are lots of reasons for that.
Livestock emits a huge amount of methane by belching. And the process of getting meat to our tables is incredibly carbon intensive.
For example we deforest land to make space for livestock to live, and to grow crops to feed them.
This not only deprives the world of carbon-absorbing trees, but intensive farming techniques eventually degrade soil so that it releases carbon too.
And then there are the other environmental impacts - the massive amount of freshwater needed, the water, air pollution and ocean acidification associated with fertilisers and pesticides, as well as a reduction in biodiversity.
The UN's Intergovernmental Panel on Climate Change (IPCC) has said that a plant based diet can help tackle the climate crisis.
And the Oxford study went further - it said that to have a chance of keeping global warming under a 2C rise the entire world needs to shift to a "flexitarian" diet.
That means consuming 90% less pork and 75% less beef while also quadrupling the amount of nuts and seeds and tripling beans and pulses.
The stakes are quite high on this one.
A failure to dramatically reduce meat and dairy consumption could mean that we will not only miss our climate targets but also that we could struggle to feed the planet's projected population of 10 billion people by 2050.
The farming industry, those who understand best how to manage the land, will play a huge part in a shift that apparently must come - much has been made, for example, of the role grazing animals can play in more sustainable agriculture.
Still, there are obviously huge challenges ahead for an industry that creates and sustains jobs, wealth, and products that millions of people like to consume.
And while I'm not arguing that the production and consumption of plant based diets is environmentally perfect, I still think the case for cutting down meat and dairy is really clear.
There seem to be so many risks if we don't, and so many benefits if we do.
What I also believe is that, and I'm speaking from personal experience now, relying only on the good will of people to make the "right" choice when faced with racks of well-priced tasty meat and dairy just simply isn't going to work, especially as global income rises and more people can afford and demand it.
I can't believe I'm writing this but I need the nanny state's help.
Taxes, subsidies, education from an early age - you know - proper assistance with behaviour change.
Because if the environmental footprint of meat and dairy is as large and destructive as is being suggested, and we can do something about it without asking individuals to make a huge sacrifice, then why aren't global governments making this a priority?
Hannah Thomas-Peter is climate change correspondent based in New York, covering a range of environmental stories around the world. Hannah has taken part in a month-long sailing expedition around Britain for a documentary examining the problem of ocean plastics.
First published in Sky News