'Hope' is written in huge letters on the side of our coach, but the word that has been used just as often - in speeches, chanted at rallies and in conversations all along the route - is justice.
The caravan may be a celebration of Africa's flourishing climate change movement. But it is also a show of strength; a sign that African activists know their rights and are ready to demand them. As one of the few people on board the bus from an industrialised country, the activists' speeches have made for uncomfortable listening at times.
I squirmed in my seat in Bujumbura, I squirmed on the terraces at Kampala rugby club, I am squirming now in a city centre hall in Nairobi and I expect to keep squirming all the way down to Durban.
The idea of climate justice - that the burden of responsibility for climate change lies with industrialised countries and so it is their duty to make amends - is expressed with such simplicity and clear moral logic, that it feels embarrassing that African activists have to ask for it at all.
And it is even more shaming when you hear about the impact that climate change is already having on Africans themselves, via the accounts of a Burundian farmer, a Ugandan activist, a Maasai musician.
The caravanites have made it very clear what they expect of industrialised countries at the Durban negotiations: commitments to ensure significant cuts in carbon emissions and funding to help developing countries adapt to a low carbon future.
But I wondered what they had to say to ordinary people and campaigners in industrialised countries, who would have been squirming, along with me, if they'd had the chance.
'We want them to lobby their politicians and say "See what our brothers and sisters from these countries in Africa are going through,''' Kenyan climate change activist Festus Mutavi told me.
'If I as an African campaigner try to stand all alone, my voice will not get through. Solidarity between people in industrialised countries and us is crucial.'
Dar es Salaam, Tanzania
A mere 18 hours on the bus yesterday. Our rather bleary-eyed group of Caravanites assembled in the lobby of our Nairobi hotel at 4am. An even more bleary-eyed group got off the bus at 10pm on the outskirts of Dar es Salaam. It was easy to be blasé about the distances we’d travel when I was sitting in London - less so yesterday morning, when I caught an unfortunate glimpse of a sign giving the distance to Dar.
Luckily, Africa was putting on a fine display for our entertainment. There was a disappointing no-show from Kilimanjaro – which was hiding behind a thick wall of cloud – but in the afternoon, we were treated to views of vivid green plains and my favourite kind of African weather: darkening skies, a slight chill and the electric tingle in the air that precedes a storm.
Scudding clouds, open road – at the risk of sounding like a middle-aged man, if I’d only had some Springsteen on my iPod; my happiness would have been complete.
But there was some fine singing (watch this short video) from Nizigama Sylvane and Urayeneza Verene, a Burundian and a Rwandan farmer respectively, who have become good friends during the journey.
As for meals, my number one fear on this trip is getting food poisoning and being forced to endure a journey like yesterday’s, a grimace on my face and queasiness in my stomach. So when we stopped at a dubious-looking foodside stall, I became the joke of the group by buying what I thought was the safest lunch option: three pieces of cake and two bananas. In the end I was shamed into having some fried chicken too. No adverse effects so far.