Hello Fred; Big volcanic eruptions loft so much fine material into the stratosphere that the climate cools for some extended period. There are now numerous documented examples. Here is an example study;
"The Medieval Climate Anomaly and the Little Ice Age in the eastern Ecuadorian Andes".
A contineous situation of volcano in a particular country or region may affect drastically physiographically and enviornmently. but need to conduct analysis what extent they responsible for climate change.
Yes, volcano producing climate through gases and dust it pollution the atmosphere and earth surface, the major gas is CO2, in general volcanoes emit around 0.3 billion tonnes of CO2 per year.
and I think another volcano (Rabaul: Nasa photo of the caldera) produced a climate change that could be seen thanks to the displacement of Isiatis tinctorial (pastel) culture, from Sahara savannas (7th c. Tuareg blue men) passing by Occitania (11th C., Cathars) up to Flanders damps (bay of Somme 14th C.). In 15th c., climate change slowed down a bit and pastel could be again cultivated in Occitania.
I consider we still have very little knowledge of what happen in high atmosphere with those volcanic micro particles with almost no weight but an electrical charge and a chemical constitution, for example, how do they interact with solar particles reaching Earth's atmosphere? I think they can perform high atmosphere lightening that can reach Earth, attracted by its mass, where it would provoke "spontaneous" fires in forests.
Although an asteroid is normally claimed nowadays as the reason for the dinosaurs' speedy disappearance, with resultant clouds shutting out sunlight for years and tsunami covering the continents, a competing hypothesis is a string of super (very large) volcanoes exploding simultaneously over a number of years. This theory has once again come to the fore.
Roughly 70 to 60, 000 BCE a huge volcano exploded in India, decimating the recent human population there and causing a delay in human populating of South Asia.
Its means volcano is one of the important factor contributing climate change and even most of the environmental parameters like, soil, air, sir temp., soil temp., gases comp. etc.